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For a Given node of a binary tree, print the K distance nodes. Find the distance between 2 nodes in Binary Tree Find the distance between 2 nodes in Binary Tree Program to count leaf nodes in a binary tree Friend Circle - Hackerrank Lazy Caterer's sequence Lego Blocks Problem K reverse a linked list with increasing K Convert Binary Tree to Doubly linked list in level order Doubly linked list ADT Find the maximum distance covered using n bikes Foldable Binary Trees - Given a binary tree, find out if the tree can be folded or not. Given a node in binary tree - Check if left and right subtree are mirror of each other Union and Intersection of two unsorted Linked Lists Union and Intersection of two sorted arrays Given two strings str1 and str2, write code to find out if all non-unique elements in str2 are in str1? Algorithm Interview Questions - Set 1 Design Questions - Set 1 Given an array arr[], find the maximum j – i such that arr[j] > arr[i] Given an array arr[], find the maximum j – i such that arr[j] > arr[i] Finding IP Address from hostname in Windows Linux and Unix Skiplist vs Binary tree Skiplists Max submatrix sum in a matrix Find max subsquare whose border values are all 1 Transform one word into another by changing only one letter at a time Search a long string for small strings in an array Pattern Searching - Boyer Moore Algorithm – Bad Character Heuristic Searching Patterns - Finite Automata Rabin-Karp Algorithm Suffix Array Suffix tree Longest word made of other words in an array Find largest 1M numbers in 1B numbers Shortest distances between two words in a file Count the number of 2s between 0 and n Randomly generate m integers from an array of size n Find pairs of integers in an array that sum to a value Implement rand7() using rand5() Algorithm Analysis Variables and Data Types Introduction Encode XML Find the frequency of a word in a book Generate english phrase that describes a integer Game of Master Mind Find the maximum (or minimum) of two numbers (or morenumbers) without use of comparison operators or if-else Number of trailing zeros in a factorial Check if someone has won tic-tac-toe Road Race Sum of Hats Coins on the Table Coins on the Table 40 Pounds in the Balance Crazy guy in Airplane Monty hall problem - Choose the Correct Door Cigars on Circular Table Measure 45 minutes Cards with Vowel & Even number Wire Connections OLD MONKS Handshakes at Party Key Exchange Puzzle Russian Roulette Cut a rectangular Cake Rope Around EARTH THE DEVIL & COLORED HATS Black and white hats - Who knows what he is wearing Prisoners and Boxes Prisoner and lightbulb Travelling MONK Leap year Birthday Crossing the BRIDGE past the GUARD NEWYORK HAIR (Pigeonhole Principle) Paying with RINGS The MISSING Servent TRUTH OR LIES Engineers & Managers Worm Crawls undefined Given 9 Dots, draw 4 Lines without picking up pen Putting numbers in 3X3 matrix - s.t. Rows OR columns or diagonals add till 15 Robots on a line Brothers and sisters Using 5,5,5,5,5 can you make 37 along with any arithmetic operation. Make 3 3 7 7 equal to 24 Make 3 3 7 7 equal to 24 Cards in the Dark Islanders with dotted forheads Get the job puzzle ATM Money Withdrawal Limit Number the 8 boxes so that no consecutive numbers touch Number the 8 boxes so that no consecutive numbers touch Minimum Sips Aeroplanes round the world River, Soldiers & Boat and children Measure weights in balance Last ball of Red Balls & Blue Balls Deck of cards - Pick the cards with same color Honest Man and single Question Elephant and Bananas Why does mirror lies sometimes? Average salary of n people in the room Point inside a triangle or NOT Triangle Formation Find the average of n numbers Fill a magic square of size n, n being odd CTRL+A, CTRL+C, CTRL+V CTRL+A, CTRL+C, CTRL+V Guess the solution of selecting 4 balls from set of 4 different colors Point inside a rectangle or not Given a number x, less than 100. How will you generate true with probability x/100. Given a number 123456789, two opearators + and *, value k , find all the such expressions that evaluates to the given value k Form a circle from 3 points How many time function gets called? Polite Numbers - Calculate all the ways such that a number can be written as sum of 2 or more consecutive numbers Find average of a stream of the numbers Print all sequences of given length Number of Subsets without consecutive elements Maximum subset of Cuboid boxes that can fit into one another REST vs RPC A Needle in the Haystack Match two board configurations of tic-tac-toe problem Given a set of numbers [1-N]. Subsets such that the sum of numbers in the subset is a prime number. Petrol Bunk in a Circle. Get Sentence from raw text Get Sentence from raw text Count the number of digits in the number Finding the next palindrome for the given number Finding the next palindrome for the given number Given the push and pop sequence on stack, verify if corresponding sequence is correct or not Data structure and algorithm interview question for java programmers Memory requirement of a program in java Hash Functions Symbol table data structure Fit 1*2 dominos in 2*N strip Atomicity and Atomic operations Selection Algorithms Deterministic Selection - Select the i th smallest element Find kth largest element from a 2-d sorted array Nut and Bolt Problem (OR Key and Lock Problem) - Matching Nuts and Bolts when nuts cannot be compared with nuts and bolts with bolts Cracking the coding interview questions Solve Towers of Hanoi using stack Find the nearest numbers that have same number of 1s for an integer Can two threads call a synchronized method and normal method at the same time? Scheduling method calls in sequence Thread safe and exception safe singleton design pattern How to measure the time spent in a context switch Suggest the selling time and buying time of a share based on stock price prediction Maximum product sub-array Set cover Create the REV function from Swap Is there multiply function in 8085 microprocessor Stone thrown from the boat Number of rectangles in MxN matrix. Three children Black Dog, Black-out and Driver Problem Inhereting wealth from wise Sheikh Book worm Alarm clock with snooze interval of 9 The U2 riddle Eggs on slanted roof Eye color of bus driver The missing dollar What is special about the following sequence of numbers? Get the matching pair out from 12 pair of black and white socks Move one DIGIT Find the longest oscillating subsequence Find the appropriate data structure Common routing protocol Compare and contrast IPv4 and IPv6 What is a network/subnet mask What happens after typing a URL into a browser Trie Tutorial Allocate a two dimensional array using one call of malloc in C Aligned malloc in C Device FIFO queue problem Prevent reverse engineering of DLLs How to make sure a process doesn’t access unauthorized part of stack What happens after a user presses a key on the keyboard? Direct memory access(DMA) Branch Target buffer Virtual memory, page fault and thrashing How to swap two String variables in java without using a third variable ER diagram for a database of company ER diagram for a database of company What is denormalization? Count the number of calls of put() and get() for a map in Java Object reflection in Java final, finally and finalize in Java Finally block and return statement Private constructor in Java Smart pointer in C++ Take a pointer to a Node structure as a parameter and return a complete copy of the passed-in data structure Searching Questions Find the duplicate element most number of times in array of 0 to n-1 Destructor in base class needed to be virtual in C++ “volatile” keyword in C (and Java) Deep copy and shallow copy in C++ Find all the words of Length N which are produced by natural order Virtual functions in C++ Compare and contrast a hash table vs. an STL map Print the last K lines of a file using C++ How to detect duplicate documents in billions of urls Design a database with terabytes of data that supports efficient range queries Fizz Buzz Fizz Buzz Finding the celebrity group The Celebrity Problem How to avoid getting into infinite loops when designing a web crawler Find duplicate elements in the array with 4KB memory only Generate an integer which is not in a file with 4 billion integers, limited memory Sorting 10 GB file of integer with limited ram. How to test an ATM in a distributed banking system How to test a pen Load test a webpage without using any test tools How to test a canMoveTo(int x, int y) method in a chess game Find the mistake(s) in the code Programming errors cause program crashes in different places every single time Check if array contains duplicates Find duplicates in the ranged array Find the two repeating elements in ranged array Find the two non-repeating elements in a ranged array of repeating elements Find the kth number with prime factors 3, 5 and 7 Find a line which passes the most number of points Find a line to cut two squares in half Implement *, -, and / operators using only + Determine whether two lines would intersect on a Cartesian plane One shot or at least two shots in three games? Three Gods - God of Truth, Lies and Chaos Labour and work problem - 20 women replaced by a men and boy alternatively Circus tower sorting problem Searching in a sorted array of strings with empty strings Sorting a 2GB file with one string per line Sort an array of strings so that anagrams are next to each other Merge two sorted arrays - One having big enough buffer to hold another Eight Queen Puzzle (likewise N Queen) Number of ways of representing n cents using quarters, dimes, nickels and pennies Implement the “paint fill” function Print all combinations of n balanced parentheses LATIN SQUARE” and its implementation Permutations of every subset of size K All possible paths for a robot moving along a NxN grid How many lockers are open after 100 passes of toggles Two egg puzzle Interval Search Tree Segment trees VS Interval trees VS binary indexed trees VS range trees Merge Overlapping Intervals How long does it take to remove c ‘magical’ hats from n people Remove duplicates from unsorted array Number of unique elements in sorted array with repeated elements Get 4qt of water using a 5qt jug and a 3qt jug Covering a chess board with dominos Sieve of Atkins Algorithm to find out number of factors of a number Program to print all prime factors of a given number To find the list of primes till N Sieve of Eratosthenes Efficient ways to check if number is prime number Given a series (2,3,4,5,6,8,9,10,12,15,...) where the elements are in multiple of 2,3 and 5. Find the nth element of this sequence Check if 2 trees are iso-morphic Check if any number exists in the list after removing them from particular positions in natural number progression Swap odd and even bits in an integer Avid TV watcher Find missing integer in an array with only access to jth bit of element A[i] Division without using *, / or % (Divide Two Integers) Count total set bits in all numbers from 1 to n Next Power of 2 Count number of bits to be flipped to convert A to B Some useful resources Explain ((n & (n-1)) == 0) Print binary representation of a decimal number Print binary representation of a decimal number You have two very large binary trees: T1, with millions of nodes, and T2, with hundreds of nodes Create an algorithm to decide if T2 is a subtree of T1 Print all paths in a binary tree which sum up to a value Finding the biggest difference between sorted array values Set all bits of a number in a range equal to another number Add arithmetic operators to make 3 1 3 6 = 8 true Find all pairs (x, y) in a sorted array so that x + y < z Divide a number by 3 without using *, /, +, -, % operators Add two numbers without using arithmetic operators Divide a number by 3 without using any of operators (%,/,*) Add 1 to a given number without arithmetic operators Strings index Unique Paths in 2D grid Implement a stack using queue Find Local Minimum in an unsorted array with unique elements Find Local Minimum in an unsorted array with unique elements Sorted Linked List to Balanced BST Convert sorted array to Balanced BST Implement a stack using 2 queues Stack with find-min/find-max in O(1) time Algorithm Introduction Find the minimum and maximum in the array Find Maximum Value in the unsorted array Find kth largest in an Array find out the largest and second largest number in an array find out the largest and second largest number in an array How to find max. and min. in array using minimum comparisons? Determine if a small tree T2 is the subtree of a huge tree T1 Create linked lists of all the nodes at each depth for a BST Find if there is a path between two vertices in a directed graph Find if there is a path between two vertices in a directed graph How to check whether a given number n belongs to fibanocii series? Find next higher number using exact same digits Stack of plates Implementing 2 stacks in an array Provide an algorithm such that if an element in an MxN matrix is 0, its entire row and column is set to 0 Rotate n * n matrix by 90 degrees Rotate n * n matrix by 90 degrees Determine if a string has all unique characters Algorithm to find top 10 search terms in search engine Find the k most frequent words from a file Given a binary tree with extra field "next pointer" in node, populate the next pointer to the nodes inorder successor Data Structure to Emulate LRU Cache Print nodes at k distance from root Find the time period with the maximum number of overlapping intervals Given an array of 100,000 pixel color values and each of which is an integer in the range (0,255). Give sorting algorithm. Insertion sort on linked list Selection sort on linked list Sort a linked list using bubble sort Sort a linked list using quick sort Bubble sort on double linked list Sort a linked list using merge sort What's the fastest algorithm for sorting a linked list? Find increasing 3-tuple (sub-sequence) Merge two arrays efficiently - one sorted, another unsorted Sorting implementation in c Red Black Tree vs AVL Tree vs B-Tree Union Find Bottom-up Merge Sort Given an integer array of which both first half and second half are sorted. Write a function to merge the two parts to create one single sorted array in place [do not use any extra space]. Amazon Questions - Set 1 k-way merge - Merging k sorted arrays of n elements Find the maximum repeating number in array where all the elements are in range 0 to k-1, k ∈ [0,N] Finding the max repeated element in an array Print letters followed by their frequency (Run Length Encoding) Remove duplicate characters in a string Find first non repeating character in a string Reverse a c-style string Eliminate the pairs (two same chars adjacent to each other) in string Move the Spaces to Front of the String Replace all spaces in a string with “%20″ in c-style string How many possible ways the child can run up the ladder Find row with maximum number of 1s in sorted matrix Company specific interviews Find Position of the only Set Bit Checking if a bit is on or off without affecting other bits Toggle a specified bit in a bit string without effecting other bits Divide a number by a power of two using bit right shift Multiply a number by a power of two using bit left shift Find largest Binary Search Tree in a Binary Tree Convert Binary tree to Binary Search Tree conversion in place Write code to find nth largest number from a stream of numbers. Given a stream of characters, find the kth non-repeated character at any given time. Given a stream of characters, find the kth non-repeated character at any given time. Find all the pythagorean triplets in an array of integer 3 sum problem Maximum value in a Sliding Window Container With Most Water Arrays Index Maximum weight independent set (WIS) graph problem using DP Sequence Alignment using Dynamic Programming Application of clustering Minimum Spanning tree MST Binary Tree Level-Order Traversal Using Depth First Search (DFS) [Not to USE BFS] Binary Tree Post-Order Traversal - Recursive and Iterative Solution Binary Tree In-Order Traversal - Recursive and Iterative Solution Find the rank w.r.t K - Number of nodes with value less than K Iterators - Allowing iteration over data structures (in java) Generic data structures in java Evaluating postfix expression using stack Converting an Infix Expression to Postfix expression using a stack Checking whether the paranthesis are balanced in the expression Resizing Array implementation of stack Introduction of Array find four elements in array whose sum equal to a given number X Balanced Binary Search Tree Index AVL Tree Index AVL Tree Index BFS (Breadth first search) on Graph DFS (Depth first search) for graph Dijkstra's algorithm for equal weight edges using BFS Deleting the element from the heap Application of heap (in computer science) Building of heap Array Implementation of Heap Array Implementation of Heap Find Nth largest element in the rotated sorted array Find Nth largest element in the rotated sorted array Find the rotation count in rotated sorted array Random Contraction Algorithm Graph Representations Cuts of Graphs Integer Multiplication using Karatsuba algorithm Red Black Tree Index Data Type in Data Structure Pathological Data Sets and Universal Hashing Motivation Hash Tables Given a dictionary of word - Group all words into set of anagrams of each other Splay trees Boyer Moore Algorithm Sorting Tower of Hanoi Problem Implementing doubly linked list using single pointer Rearranging linked list first odd next even numbers GetMin and GetMax in BST Binary tree - Types and Properties Linear Search on Array Randomized Algorithm Bellman ford algorithm - One source shortest path Strongly Connected Graph Topological Sorting Minimum Cut Problem Closest Pair Algorithm Randomized Selection : Selecting the i'th smallest element Meaning behind Master Method Master Method for Solving Recurrences Strassen's Subcubic Matrix Multiplication Algorithm Inversions BFS and Undirected Connectivity Dijkstra's Shortest Path Algorithm Adjacency list represention of graph in Java Graph Search Introduction How do I check if a number is a palindrome? How do I check if a number is a palindrome? Operation time complexity for a LINKED LIST Operation time complexity for an ARRAY Time complexity - Omega of algorithms Time complexity of algorithms - In particular Big Omega of algorithms String Searching Algorithm - Knuth Morris Pratt or KMP Algorithm Priority Queue What is a non-linear datastructure? What is a linear datastructure? What is a sorting algorithm? Insertion sort Introduction to Heap Selection Sort What is Bucket Sort? What is a Graph data structure? Graph Traversal Methods Find shortest path using Dijkstra's Algorithm Hashing, Hash Data Structure and Hash Table What is a Complete Binary Tree? Binary tree traversal: Preorder, Inorder, Post-order, BFS, DFS, Level Order, zig zag order Data Structure Introduction About Legal Circular Stack Red Black Tree – Insertion Red Black Tree – Deletion Bloom filters AVL Tree : Deleting a node from AVL Tree AVL Tree : Rotations Bitonic Sort Bidirectional Bubble Sort Priority Queue based on Sorted Linked Lists Sorting in Hungarian Way How to rotate an array? 2 Sum Problem : Given an integer array and a number T, find all unique pairs of (a, b) whose sum is equal to T 2 Sum Problem : Given an integer array and a number T, find all unique pairs of (a, b) whose sum is equal to T Printing "Hello World" to screen without using a single semicolon in C/C++ Printing "Hello World" to screen without using a single semicolon in C/C++ Construct a full binary tree from a pre-order list of marked nodes Converting integers less than 100 to words Find all subsets of a given set OR Find power set of a given set Find all subsets of a given set OR Find power set of a given set Turning a bit off without affecting other bits Bit Manipulation Tips and Tricks Removing a loop in a singly linked list Finding an integer that repeats odd number of times in an array of positive integers Maximum continuous sum subarray problem Maximum continuous sum subarray problem Andersson Trees ArrayDeque + Stack Algorithms Sorted Linear Hash Table Search trees AVL Trees : Inserting a new Item Concurrent Skip List Huffman Codes Convert Binary tree to double linked list in inorder traversal Find the First Duplicated Integer in an Array containing numbers from 1 to N Without Using Extra Memory Find the First Duplicated Integer in an Array containing numbers from 1 to N Without Using Extra Memory Sorting Array of Three Kinds or The Dutch National Flag Problem OR three color sort Shuffle a deck of cards perfectly Find Local Maximum of a Function Using Bisection Method Least-Square Linear Regression of Data Using C++ Convert integers to roman numbers Check If an Integer's Bit Representation Is a Palindrome Convert Binary Tree to Double Linked List in Zig-Zag Order Minimum Distance Between Two Elements in an Array Difference Between Sums of Odd and Even Levels in Binary Trees Find common nodes from two linked lists using recursion Y – shaped Linked List. Algorithm to find the node of intersection of two lists. Remove duplicates from an unsorted linked list print the sum( inclusive of the root ) of sub-tree rooted at each node in in-order in Binary Tree Print pascal's triangle What does flattening list of items into tree means B + tree B-tree BTree in java Red Black tree Heap Sort in java Binary heap : Introduction Heap : Removing the min element using BubbleDown Heap : Inserting an element into a heap using BubbleUp Convert array of positive numbers to sorted array Implement Add,Subtract,Multiplication,Division Using Bit Manipulation K – Reverse a linked list Find the point of transition from 0 to 1 in an infinite sorted array containings only 0 and 1 . Find the point of transition from 0 to 1 in an infinite sorted array containings only 0 and 1 . Searching the element in sorted infinite array of integers Minimum number of coins to get particular amount, given multiple denomination Get maximum sum from coins in a line Find optimal number of jumps to reach last element Max possible sum of non-consecutive elements Max possible sum of non-consecutive elements Maximum size square sub-matrix with all 1s Find largest sub-matrix with all 1s (not necessarily square) Maximum Area Rectangle in Histogram Iterative or Non recursive Inorder traversal on tree DFS (Depth First Search) on tree or graph BFS (Breadth first search ) OR Level Order Traversal on tree Check if 2 strings are rotated versions of each other Syntax highlighter for blogs Escape all % characters in a string; % is the escape character Remove whitespace from a string in-place, in linear time Remove whitespace from a string in-place, in linear time Implementing strcpy Implementing strcat Implementing strcmp Double Linked List Structure First non repeating element in the array Find anagrams in the array of Strings Gold bar with 7 segments Implementing a strstr() / indexOf function Combination of all the possible characters in the string Concatenate N strings with good optimization Check if Tree is a Balanced Tree Some Stack Question Implement 3 stacks in 1 array Implement a queue in which push_rear(), pop_front() and get_min() are all constant time operations. Find the minimum element in the rotated sorted sorted array Find the minimum element in the rotated sorted sorted array Search an element in the sorted rotated array Reverse a String using bits Pick a Random Byte Three Switches and Three Blub Problem Deleting a node from a singly linked link list Link list ADT Calculate length of the linked list that contains loop Add 2 large numbers in the form of list, without reversing the linked lists Sorting a very large file which cannot fit in memory Stack DS to implement constant time Minimum element lookup Print a Binary Tree in Zig Zag Level Order or spiral order Finding the Start of a Loop in a Linked List Finding the Start of a Loop in a Linked List GitHub: Setup SSH - Permission denied public key error Karp-Rabin algorithm Given a 10 digit number,find the greatest continuous 4 digit number. WAP to Find Number of Divisor & sum of All Proper Devisor of Number Efficiently Find Diameter of Binary Tree Find Diameter of Binary Tree Flipping Coins on the table How to reverse a stack in place ? Reaching the door of Heaven Random Selection from a Linked List Use some Datastructure to get O(1) stack operations Next Greater Element in an array Next Greater Element in an array Folding BSTs Diameter of a Binary Tree Remove Character From String1 which are present in String2 Longest increasing subsequence Vertical Sum of a Binary Tree Vertical Sum of a Binary Tree Prove that number between twin primes is divided by 6 How can you properly devide the hotel charges? Passengers and Random Seats in Airplane Find whether a given number N is of the form 2^x + 2^y (^ means exponentiation, x and y are positive). Find out the matching socks Minimax (Minmax) Search Find an element in matrix in which rows and columns are sorted Find first occurrence of a string in another Row consisting max continuous chain of 1’s in an n * n grid Convert a Number (unknown base) to a Base 10 Number Majority element in the array encodeURIComponent and decodeURIComponent in Java atoi() in Java In-Place Character Array Compression itoa() in Java Trie Operations Complexity Trie : Searching in Trie Trie : Inserting in Trie Implementing the TRIE ADT in java Trie ADT Globe Walker Trains and Birds Gold for 7 days of work The Ant Collision Problem Is Your Husband a Cheat? 50 trucks with payload Camel and Banana Red, Green and Yellow Balls - heavy and light One duplicate , one missing element in an array Given numbers from 1 to N+1, with number being from 1 and N and one of the number being repeatative. Find the repeating element. Find the smallest window in a string containing all characters of another string Deleting a node in singly linked list if it is less than any of the successor nodes Deleting a node in singly linked list if it is less than any of the successor nodes Duplicate removal in Binary Search Tree Squeeze all multiple spaces in a string into one space Given a binary tree, print the sum( inclusive of the root ) of sub-tree rooted at each node in in-order Leveling sectors in a circle To find the longest substring with unique characters in a given string Reverse the words in a sentence in place Check if singly linked list is Palindrome Spiral printing of a two dimensional array Sum of two long positive numbers (each represented by linked lists) Given a binary tree, print the sum( inclusive of the root ) of sub-tree rooted at each node in in-order k largest(or smallest) elements in an array Advantage and disadvantage of datastructures Median of 2 sorted arrays of equal size n Median of 2 sorted arrays of equal size n Find median of a linked list or a Tree Find longest palindrome in a string. Find longest palindrome in a string. Compare two string literals Anagram Checker–To check if 2 strings are anagrams Anagram Checker–To check if 2 strings are anagrams Find nth largest value in a BST Find nth largest value in a BST XML Sequence Delimiter Counting sort Sorting a Stack using push,pop,isEmpty and peek Balanced Search tree AVL tree : Introduction Implement a Queue using two stacks How to reverse a doubly linked list ? All permutations of a string All permutations of a string What is a data structure? Intersection of two sorted lists or 2 sorted arrays Scrabble Algorithms What is BST or Binary Search tree? Program to check if two rectangle overlap or itntersect Program to check if two rectangle overlap or itntersect Sum , factorial Given two sorted arrays of size m and n respectively (m >> n), how to merge them together? Interview Questions on Binary Search tree BST : Improving search by using sentinel Nth node in inorder traversal IsBST : Check whether the tree provided is BST or not Count binary search trees–Given N nodes, how many structurally BST are possible? Check whether binary tree are same or not? Double the tree such that insert new duplicate node for each node using cpp Given a BST, create a mirror of it. Given Binary Tree and sum, give root to leaf path such that all nodes add to that sum Print binary search tree in increasing order Print binary search tree in increasing order Find the minimum data value find in Binary Search tree (using cpp) Compute Maximum Depth or Height of binary search tree Getting the size of Binary Search Tree Create Copy of a tree (cpp) AA - tree implementation in java Spatial indexing with Quadtrees and Hilbert Curves Anagram Trees : Part 2 Anagram Trees Secure permutations with block ciphers BK-Treesal Why is manhole cover circular? Deleting a middle node from a single linked list when pointer to the previous node is not available Array implementation of stack Array implementation of stack int atoi( char* pStr ) Reverse a String The Circular Lake Monster Problem Arrays tip : Ignoring the zeroth row Enums in java Modifying Java Variables (w.r.t c and c++) Constructor in java 1 Common naming convention : Coding Style Improving coding style into classes Improving coding style into functions or methods Java specific naming convention Specific cases of naming enhancing naming style Java and CPP - the differences and similarities Types of constructors The stack and the heap Word Length Frequency Taking input as string 1 - " C-String to Int " Using stl sort Enum in c++ Beginning with vi Use the variable closer to its use How to bound check arrays in cpp / c File IO in c++ 1 Using == operator in better way in cpp Orthogonality Longest common substring revisited Troubleshooting DNS servers Cloud Computing and Virtualization Virtualization Storage virtualization Network virtualization Self reproducing program in C zero sized allocation using malloc return and exit from main: difference Pointer cause decay, references do not. References and Constants How to create function polymorphism in C C Strings Writing a DLL in C++ C++ STL: Iterators and Containers BWT (Burrows Wheeler Transform) Encoding Algorithm Socket Programming In C Memory Management Basics Memory Management In C and C + + Finding time of execution of code in c Reducing the space for LCS lengths Reading from file or Reading integers from file ‘exit’ was not declared in this scope Comparison sort and Integer sorts Hirschberg’s linear space algorithm in C++ Hirschberg's algorithm Dynamic Programming Algorithm (DPA) for Edit-Distance Dynamic Programming Practise Problem Set 3 Longest common substring problem Dynamic Programming Practise Problem Set 2 Matrix chain multiplication Dynamic Programming Practise Problem Set 1 Prim's Algorithm Kruskal's Algorithm Dynamic-Programming Algorithm for the Activity-Selection Problem An Activity Selection Problem ( Greedy Approach) Dijkstra's Algorithm (Shortest Path) Dynamic-Programming Solution to the 0-1 Knapsack Problem Find the nth Fibonacci number Solve the Rat In A Maze problem using backtracking. Representing the Solution Space Balancing Scales Backtracking Algorithms Divide and Conquer Optimal Substructure Overlapping subproblems in Dynamic programming Common characterstics in dynamic programming Introduction to Dynamic programming Types of algorithms Important ds question Longest common subsequence : Dynamic programming GCD and LCM External Sorting - How do you sort a million 32-bit integers in 2MB RAM? maximum index of an array Missing integers print combinations Trie examples Scrabble algorithm Permutations and Combinations of string Tries Find the distinct words from a text file superstring DFS and BFS on trees, with and without recurssion Remove duplicates from the sorted array print all word combinations from phone number String matching Sorting binary array - Array containing only 0 and 1 in one pass OR two color sort Sorting binary array - Array containing only 0 and 1 in one pass OR two color sort Write a C Program to reverse a stack "in place" using recursion ? You are given a datatype, say X in C. The requirement is to get the size of the datatype, without declaring a variable or a pointer variable of that type, And, of course without using sizeof operator ! What can be maximum memory that a process can have in 32-bit machine? What assigns a process this memory? What should be done when an exception occurs in the constructor? How do you know where the memory leaks when you have multiple files? WAP to find the number containing all the digits (1-9, no 0) such that number till nth digit is divisible by n wo teen women wali puzzle ka sol.. how to chk if a no. is integer or not. print 1-100 no.swithout loop in c Write a C program which when compiled and run, prints out a message indicating whether the compiler that it is compiled with, allows /* */ comments to nest. Find the nth Ugly Number Given a string s1 and a string s2, write a snippet to say whether s2 is a rotation of s1 using only one call to strstr routine? (eg given s1 = ABCD and s2 = CDAB, return true, given s1 = ABCD, and s2 = ACBD , return false) Reverse a linked list Remove duplicates from a sorted linked list Insert nodes into a linked list in a sorted fashion Return the nth node from the end of a linked list Binary search on a linked list C program to free the nodes of a linked list Copy of a linked list Compare two linked lists Middle of a linked list Basic functions of link list - Add and print Function to add node to double link list Detecting a loop in a linked list Comparing floats Solution - #104 Project Euler Simplified IP Addressing Write a recursive function that, given the number of distinct values, computes the number of structurally unique binary search trees that store values from 1.....N. Some cardinals Tree BST - Index Threaded binary tree Construct a tree given its inorder and preorder traversal strings. Similarly construct a tree given its inorder and post order traversal strings. Given an expression tree, evaluate the expression and obtain a paranthesized form of the expression. First / Lowest common ancestor (LCA) of 2 node in binary tree Pre Order traversal - Recursive and Iterative solution Find the median in a continous stream of numbers Circular Queue Bubble sort Stack implementation using linked list Quick sort Radix sort Merge Sort Fibonacci, triangular, square, cube, pentagon numbers Array of 0 and 1, put 0's at even position and 1's at odd position Anagram program implentation Finding whether 2 arrays are intersecting Convert integer into a binary number Binary search on Array - Recursive and iterative Euclid's Algorithm : GCD of 2 integers Given an array of n integers from 1 to n with one integer repeated twice Data Structures Interview Questions (Theoritical) Basic Mathematics in Algorithms Given a list of n numbers from 1 to n-1, with one of the numbers repeated. Devise a method to determine which number is repeated Give a fast way to multiply a number by 7 Bresenham's circle algorithm Line Drawing Algorithms Routine to draw a circle (x ** 2 + y ** 2 = r ** 2) without making use of any floating point computations at all. Reversing a number To reverse the bits in an integer Check if the 20th bit of a 32 bit integer is on or off? Count bits set in an integer c program without main Basic Interview Questions on networking Various Software model Left most n digits divisible by n math.h Chain Cut Problem CTS Aptitude Question paper(Yellow) CTS Aptitude Question paper(Yellow) CTS Aptitude Question paper(Yellow) PSYCHOMETRY TEST Learn some words Ten Horses and Nine Stable Problem (Focus on word) Questions on various topics Verbal questions 2 Verbal questions - mixture of words File Handling in c Random number generation General Utilities Error handling Random access functions File handling in cpp Using pointers to break into bytes #ifdef & #endif sizeof operator Using pascal keyword Ratio and proportion difficult questions Ratio and proportion difficult questions Problems on partnership Time and Distance questions Trains Multiplication Tables Find all sets of consecutive integers that add up to 1000. The smallest no. such that if its rightmost digit is placed at its left end, the new number so formed is precisely 50% larger than the original no. Sum of last digit = sum of rest digits What is a void pointer? Why can't we perform arithmetic on a void * pointer? Program to check if the stack grows up or down How can we sum the digits of a given number in single statement? To swap the two nibbles in a byte What is a NULL pointer? How is it different from an unitialized pointer? How is a NULL pointer defined? WAP to check whether string is palindrome A program to print numbers from 1 to 100 without using loops Code to check if an integer is a power of 2 or not in a single line How does free works? Pointer indirection with care Given two strings A and B, how would you find out if the characters in B were a subset of the characters in A? What's the difference between const char *p, char * const p and const char * const p? Syntax in C Access non const member varible inside a const member function How to add two numbers without using the plus operator? What are the common causes of pointer bugs? What is the difference between malloc() and calloc()? Convert the decimal number to any base (binary, hex, oct etc...) C code to dynamically allocate one, two and three dimensional arrays (using malloc()) What is a dangling pointer? What are reference counters with respect to pointers? To add two long positive numbers (each represented by linked lists in C) How to find out if a machine is 32 bit or 64 bit? Operator Precedence in C & CPP What's Database Normalization ? What's an RDBMS ? Types of Databases What is a Database? Acronyms used in operating system Going beyond range of datatype Extern keyword Using ## and # with define. Return values of some functions in c The preprocessor directives can be redefined anywhere in the program Given a rectangular (cuboidal for the puritans) cake with a rectangular piece removed (any size or orientation), how would you cut the remainder of the cake into two equal halves with one straight cut of a knife ? How does throwing and catching exceptions differ from using setjmp and longjmp? What is the difference between goto and longjmp() and setjmp()? Besides communication cost, what is the other source of inefficiency in RPC? Given an eight-bit bitmap graphics file, devise an algorithm to convert the file into a two-bit ASCII approximation Given the time, devise an algorithm to calculate the angle between the hour and minute hands of an analog clock Efficient code for extracting unique elements from a sorted list of array Given only putchar (no sprintf, itoa, etc.) write a routine putlong that prints out an unsigned long in decimal Some macros Using define without assigning value To determine whether machine is Little-Endian and Big-Endian? 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C preprocessor Complicated Declaration Program string class Pattern matching program using Brute Force Algorithm Program to manage array of pointers to strings Program with the use of array of pointers to strings Program to manage a 2-D array of Characters Making a String class in cpp Program to multiply two polynomials Program to Add two polynomials Program for matrix operations like determinant, singular, etc. Program to perform operations like addition, multiplicaton, etc. on matrix Program to merge two 1-D arrays Representing Arrays as a class in cpp Why

Max submatrix sum in a matrix Find max subsquare whose border values are all 1 Transform one word into another by changing only one letter at a time Search a long string for small strings in an array Longest word made of other words in an array Find largest 1M numbers in 1B numbers Shortest distances between two words in a file Count the number of 2s between 0 and n Randomly generate m integers from an array of size n Find pairs of integers in an array that sum to a value Implement rand7() using rand5() Encode XML Find the frequency of a word in a book Generate english phrase that describes a integer Game of Master Mind Find the maximum (or minimum) of two numbers (or morenumbers) without use of comparison operators or if-else Number of trailing zeros in a factorial Check if someone has won tic-tac-toe Cracking the coding interview questions Solve Towers of Hanoi using stack Find the nearest numbers that have same number of 1s for an integer Can two threads call a synchronized method and normal method at the same time? Scheduling method calls in sequence Thread safe and exception safe singleton design pattern How to measure the time spent in a context switch Common routing protocol Compare and contrast IPv4 and IPv6 What is a network/subnet mask What happens after typing a URL into a browser Allocate a two dimensional array using one call of malloc in C Aligned malloc in C Device FIFO queue problem Prevent reverse engineering of DLLs How to make sure a process doesn’t access unauthorized part of stack What happens after a user presses a key on the keyboard? Direct memory access(DMA) Branch Target buffer Virtual memory, page fault and thrashing ER diagram for a database of company ER diagram for a database of company What is denormalization? Count the number of calls of put() and get() for a map in Java Object reflection in Java final, finally and finalize in Java Finally block and return statement Private constructor in Java Smart pointer in C++ Take a pointer to a Node structure as a parameter and return a complete copy of the passed-in data structure Destructor in base class needed to be virtual in C++ “volatile” keyword in C (and Java) Deep copy and shallow copy in C++ Virtual functions in C++ Compare and contrast a hash table vs. an STL map Print the last K lines of a file using C++ How to detect duplicate documents in billions of urls Design a database with terabytes of data that supports efficient range queries How to avoid getting into infinite loops when designing a web crawler Find duplicate elements in the array with 4KB memory only Generate an integer which is not in a file with 4 billion integers, limited memory How to test an ATM in a distributed banking system How to test a pen Load test a webpage without using any test tools How to test a canMoveTo(int x, int y) method in a chess game Find the mistake(s) in the code Programming errors cause program crashes in different places every single time Find the kth number with prime factors 3, 5 and 7 Find a line which passes the most number of points Find a line to cut two squares in half Implement *, -, and / operators using only + Determine whether two lines would intersect on a Cartesian plane One shot or at least two shots in three games? Circus tower sorting problem Searching in a sorted array of strings with empty strings Sorting a 2GB file with one string per line Sort an array of strings so that anagrams are next to each other Merge two sorted arrays - One having big enough buffer to hold another Eight Queen Puzzle (likewise N Queen) Number of ways of representing n cents using quarters, dimes, nickels and pennies Implement the “paint fill” function Print all combinations of n balanced parentheses All possible paths for a robot moving along a NxN grid How many lockers are open after 100 passes of toggles Two egg puzzle How long does it take to remove c ‘magical’ hats from n people Get 4qt of water using a 5qt jug and a 3qt jug Covering a chess board with dominos Swap odd and even bits in an integer Find missing integer in an array with only access to jth bit of element A[i] Count number of bits to be flipped to convert A to B Explain ((n & (n-1)) == 0) Print binary representation of a decimal number Print binary representation of a decimal number You have two very large binary trees: T1, with millions of nodes, and T2, with hundreds of nodes Create an algorithm to decide if T2 is a subtree of T1 Print all paths in a binary tree which sum up to a value Set all bits of a number in a range equal to another number Add arithmetic operators to make 3 1 3 6 = 8 true Add two numbers without using arithmetic operators Convert sorted array to Balanced BST Determine if a small tree T2 is the subtree of a huge tree T1 Create linked lists of all the nodes at each depth for a BST Find if there is a path between two vertices in a directed graph Find if there is a path between two vertices in a directed graph Stack of plates Provide an algorithm such that if an element in an MxN matrix is 0, its entire row and column is set to 0 Rotate n * n matrix by 90 degrees Rotate n * n matrix by 90 degrees Determine if a string has all unique characters Remove duplicate characters in a string Reverse a c-style string Replace all spaces in a string with “%20″ in c-style string 3 sum problem Find all subsets of a given set OR Find power set of a given set Find all subsets of a given set OR Find power set of a given set Maximum continuous sum subarray problem Maximum continuous sum subarray problem Shuffle a deck of cards perfectly Remove duplicates from an unsorted linked list Check if 2 strings are rotated versions of each other Check if Tree is a Balanced Tree Implement 3 stacks in 1 array Search an element in the sorted rotated array Stack DS to implement constant time Minimum element lookup Finding the Start of a Loop in a Linked List Finding the Start of a Loop in a Linked List Find an element in matrix in which rows and columns are sorted The Ant Collision Problem Anagram Checker–To check if 2 strings are anagrams Anagram Checker–To check if 2 strings are anagrams Sorting a Stack using push,pop,isEmpty and peek Implement a Queue using two stacks All permutations of a string All permutations of a string Deleting a middle node from a single linked list when pointer to the previous node is not available Find the nth Fibonacci number Return the nth node from the end of a linked list First / Lowest common ancestor (LCA) of 2 node in binary tree Find the median in a continous stream of numbers To add two long positive numbers (each represented by linked lists in C) To determine whether machine is Little-Endian and Big-Endian? Swap two number in place without temporary variables.

Road Race Sum of Hats Coins on the Table Coins on the Table 40 Pounds in the Balance Crazy guy in Airplane Monty hall problem - Choose the Correct Door Cigars on Circular Table Measure 45 minutes Cards with Vowel & Even number Wire Connections OLD MONKS Handshakes at Party Key Exchange Puzzle Russian Roulette Cut a rectangular Cake Rope Around EARTH THE DEVIL & COLORED HATS Black and white hats - Who knows what he is wearing Prisoners and Boxes Prisoner and lightbulb Travelling MONK Leap year Birthday Crossing the BRIDGE past the GUARD NEWYORK HAIR (Pigeonhole Principle) Paying with RINGS The MISSING Servent TRUTH OR LIES Engineers & Managers Worm Crawls undefined Given 9 Dots, draw 4 Lines without picking up pen Putting numbers in 3X3 matrix - s.t. Rows OR columns or diagonals add till 15 Robots on a line Brothers and sisters Using 5,5,5,5,5 can you make 37 along with any arithmetic operation. Make 3 3 7 7 equal to 24 Make 3 3 7 7 equal to 24 Cards in the Dark Islanders with dotted forheads Get the job puzzle ATM Money Withdrawal Limit Number the 8 boxes so that no consecutive numbers touch Number the 8 boxes so that no consecutive numbers touch Minimum Sips Aeroplanes round the world River, Soldiers & Boat and children Measure weights in balance Last ball of Red Balls & Blue Balls Deck of cards - Pick the cards with same color Honest Man and single Question Elephant and Bananas Why does mirror lies sometimes? Average salary of n people in the room Fit 1*2 dominos in 2*N strip Stone thrown from the boat Three children Black Dog, Black-out and Driver Problem Inhereting wealth from wise Sheikh Book worm Alarm clock with snooze interval of 9 The U2 riddle Eggs on slanted roof Eye color of bus driver The missing dollar What is special about the following sequence of numbers? Get the matching pair out from 12 pair of black and white socks Move one DIGIT Find a line to cut two squares in half One shot or at least two shots in three games? Three Gods - God of Truth, Lies and Chaos Labour and work problem - 20 women replaced by a men and boy alternatively How many lockers are open after 100 passes of toggles Two egg puzzle How long does it take to remove c ‘magical’ hats from n people Get 4qt of water using a 5qt jug and a 3qt jug Covering a chess board with dominos Add arithmetic operators to make 3 1 3 6 = 8 true Gold bar with 7 segments Pick a Random Byte Three Switches and Three Blub Problem Flipping Coins on the table Reaching the door of Heaven How can you properly devide the hotel charges? Passengers and Random Seats in Airplane Find out the matching socks Globe Walker Trains and Birds Gold for 7 days of work The Ant Collision Problem Is Your Husband a Cheat? 50 trucks with payload Camel and Banana Red, Green and Yellow Balls - heavy and light int atoi( char* pStr ) Reverse a String The Circular Lake Monster Problem Array of 0 and 1, put 0's at even position and 1's at odd position Chain Cut Problem CTS Aptitude Question paper(Yellow) PSYCHOMETRY TEST Ten Horses and Nine Stable Problem (Focus on word) Ratio and proportion difficult questions jelly beans Pirates sum it up Palindrome years Red marbles, blue marbles Reverse a string - word by word 17 September Solutions

Friend Circle - Hackerrank Lego Blocks Problem Convert Binary Tree to Doubly linked list in level order Number of steps required to convert string 1 to string2 when only bring character to first index operation is giving Find the largest subarray with sum of 0 in the given array Skiplists Max submatrix sum in a matrix Find max subsquare whose border values are all 1 Suffix Array Game of Master Mind Check if someone has won tic-tac-toe Sum of Hats Wire Connections OLD MONKS Handshakes at Party THE DEVIL & COLORED HATS Black and white hats - Who knows what he is wearing Prisoners and Boxes Using 5,5,5,5,5 can you make 37 along with any arithmetic operation. Make 3 3 7 7 equal to 24 Make 3 3 7 7 equal to 24 Cards in the Dark Number the 8 boxes so that no consecutive numbers touch Number the 8 boxes so that no consecutive numbers touch Deck of cards - Pick the cards with same color Triangle Formation CTRL+A, CTRL+C, CTRL+V CTRL+A, CTRL+C, CTRL+V Guess the solution of selecting 4 balls from set of 4 different colors Given a number 123456789, two opearators + and *, value k , find all the such expressions that evaluates to the given value k Maximum subset of Cuboid boxes that can fit into one another Fit 1*2 dominos in 2*N strip Selection Algorithms Common routing protocol Compare and contrast IPv4 and IPv6 What is a network/subnet mask Virtual memory, page fault and thrashing How to swap two String variables in java without using a third variable Searching Questions How to detect duplicate documents in billions of urls Eight Queen Puzzle (likewise N Queen) Algorithm to find top 10 search terms in search engine Find increasing 3-tuple (sub-sequence) Red Black Tree vs AVL Tree vs B-Tree Union Find Bottom-up Merge Sort Given an integer array of which both first half and second half are sorted. Write a function to merge the two parts to create one single sorted array in place [do not use any extra space]. Amazon Questions - Set 1 Find largest Binary Search Tree in a Binary Tree Convert Binary tree to Binary Search Tree conversion in place Binary Tree Post-Order Traversal - Recursive and Iterative Solution Binary Tree In-Order Traversal - Recursive and Iterative Solution Iterators - Allowing iteration over data structures (in java) Generic data structures in java Random Contraction Algorithm Graph Representations Integer Multiplication using Karatsuba algorithm Splay trees Implementing doubly linked list using single pointer Rearranging linked list first odd next even numbers Linear Search on Array Topological Sorting Dijkstra's Shortest Path Algorithm Graph Search Introduction String Searching Algorithm - Knuth Morris Pratt or KMP Algorithm What is Bucket Sort? Binary tree traversal: Preorder, Inorder, Post-order, BFS, DFS, Level Order, zig zag order Circular Stack Red Black Tree – Insertion Bloom filters Bitonic Sort Bidirectional Bubble Sort Construct a full binary tree from a pre-order list of marked nodes Andersson Trees ArrayDeque + Stack Algorithms Sorted Linear Hash Table Search trees Concurrent Skip List Huffman Codes Convert Binary tree to double linked list in inorder traversal Find the First Duplicated Integer in an Array containing numbers from 1 to N Without Using Extra Memory Find the First Duplicated Integer in an Array containing numbers from 1 to N Without Using Extra Memory Sorting Array of Three Kinds or The Dutch National Flag Problem OR three color sort Find Local Maximum of a Function Using Bisection Method Least-Square Linear Regression of Data Using C++ B + tree BTree in java Heap Sort in java K – Reverse a linked list DFS (Depth First Search) on tree or graph Link list ADT Calculate length of the linked list that contains loop Longest increasing subsequence Reverse the words in a sentence in place Median of 2 sorted arrays of equal size n Median of 2 sorted arrays of equal size n Program to check if two rectangle overlap or itntersect Program to check if two rectangle overlap or itntersect Count binary search trees–Given N nodes, how many structurally BST are possible? Kruskal's Algorithm Bubble sort Merge Sort Binary search on Array - Recursive and iterative Routine to draw a circle (x ** 2 + y ** 2 = r ** 2) without making use of any floating point computations at all. c program without main WAP to check whether string is palindrome Program to merge two 1-D arrays

Maximum single sell profit from stock Find the largest subarray with sum of 0 in the given array Given an array arr[], find the maximum j – i such that arr[j] > arr[i] Given an array arr[], find the maximum j – i such that arr[j] > arr[i] Find the appropriate data structure LATIN SQUARE” and its implementation Merge Overlapping Intervals Find Local Minimum in an unsorted array with unique elements Find Local Minimum in an unsorted array with unique elements How to find max. and min. in array using minimum comparisons? Find increasing 3-tuple (sub-sequence) Merge two arrays efficiently - one sorted, another unsorted Given an integer array of which both first half and second half are sorted. Write a function to merge the two parts to create one single sorted array in place [do not use any extra space]. k-way merge - Merging k sorted arrays of n elements Find the maximum repeating number in array where all the elements are in range 0 to k-1, k ∈ [0,N] Finding the max repeated element in an array 3 sum problem Introduction of Array find four elements in array whose sum equal to a given number X Array Implementation of Heap Array Implementation of Heap Find Nth largest element in the rotated sorted array Find Nth largest element in the rotated sorted array Find the rotation count in rotated sorted array Linear Search on Array Operation time complexity for an ARRAY What is a linear datastructure? Selection Sort How to rotate an array? 2 Sum Problem : Given an integer array and a number T, find all unique pairs of (a, b) whose sum is equal to T 2 Sum Problem : Given an integer array and a number T, find all unique pairs of (a, b) whose sum is equal to T Finding an integer that repeats odd number of times in an array of positive integers Maximum continuous sum subarray problem Maximum continuous sum subarray problem Find the First Duplicated Integer in an Array containing numbers from 1 to N Without Using Extra Memory Find the First Duplicated Integer in an Array containing numbers from 1 to N Without Using Extra Memory Sorting Array of Three Kinds or The Dutch National Flag Problem OR three color sort Shuffle a deck of cards perfectly Minimum Distance Between Two Elements in an Array Convert array of positive numbers to sorted array Find the point of transition from 0 to 1 in an infinite sorted array containings only 0 and 1 . Find the point of transition from 0 to 1 in an infinite sorted array containings only 0 and 1 . First non repeating element in the array Find anagrams in the array of Strings Implement 3 stacks in 1 array Find the minimum element in the rotated sorted sorted array Find the minimum element in the rotated sorted sorted array Search an element in the sorted rotated array Next Greater Element in an array Next Greater Element in an array Majority element in the array atoi() in Java In-Place Character Array Compression One duplicate , one missing element in an array Given numbers from 1 to N+1, with number being from 1 and N and one of the number being repeatative. Find the repeating element. Spiral printing of a two dimensional array k largest(or smallest) elements in an array Median of 2 sorted arrays of equal size n Median of 2 sorted arrays of equal size n Given two sorted arrays of size m and n respectively (m >> n), how to merge them together? Array implementation of stack Array implementation of stack Arrays tip : Ignoring the zeroth row How to bound check arrays in cpp / c maximum index of an array Remove duplicates from the sorted array Sorting binary array - Array containing only 0 and 1 in one pass OR two color sort Sorting binary array - Array containing only 0 and 1 in one pass OR two color sort Find the median in a continous stream of numbers Bubble sort Finding whether 2 arrays are intersecting Given an array of n integers from 1 to n with one integer repeated twice C code to dynamically allocate one, two and three dimensional arrays (using malloc()) Efficient code for extracting unique elements from a sorted list of array Initialising arrays Multi-dimensional arrays Program to manage array of pointers to strings Program with the use of array of pointers to strings Program to manage a 2-D array of Characters Program to merge two 1-D arrays Representing Arrays as a class in cpp

Asymptotic Notation Growth Rate - The Importance of Asymptotics Algorithm Interview Questions - Set 1 Given an array arr[], find the maximum j – i such that arr[j] > arr[i] Given an array arr[], find the maximum j – i such that arr[j] > arr[i] Algorithm Analysis Deterministic Selection - Select the i th smallest element Finding the celebrity group Find all pairs (x, y) in a sorted array so that x + y < z Algorithm Introduction Find next higher number using exact same digits Maximum value in a Sliding Window Closest Pair Algorithm Randomized Selection : Selecting the i'th smallest element Meaning behind Master Method Master Method for Solving Recurrences Strassen's Subcubic Matrix Multiplication Algorithm Inversions Time complexity - Omega of algorithms Time complexity of algorithms - In particular Big Omega of algorithms String Searching Algorithm - Knuth Morris Pratt or KMP Algorithm Introduction to Heap What is a Graph data structure? Finding an integer that repeats odd number of times in an array of positive integers Huffman Codes Convert integers to roman numbers Karp-Rabin algorithm Find the smallest window in a string containing all characters of another string Program to check if two rectangle overlap or itntersect Program to check if two rectangle overlap or itntersect Spatial indexing with Quadtrees and Hilbert Curves Anagram Trees Secure permutations with block ciphers BK-Treesal Reducing the space for LCS lengths Hirschberg’s linear space algorithm in C++ Hirschberg's algorithm Dynamic Programming Algorithm (DPA) for Edit-Distance Dynamic Programming Practise Problem Set 3 Longest common substring problem Dynamic Programming Practise Problem Set 2 Matrix chain multiplication Dynamic Programming Practise Problem Set 1 Prim's Algorithm Kruskal's Algorithm Dynamic-Programming Algorithm for the Activity-Selection Problem An Activity Selection Problem ( Greedy Approach) Dijkstra's Algorithm (Shortest Path) Dynamic-Programming Solution to the 0-1 Knapsack Problem Find the nth Fibonacci number Solve the Rat In A Maze problem using backtracking. Representing the Solution Space Balancing Scales Backtracking Algorithms Divide and Conquer Optimal Substructure Overlapping subproblems in Dynamic programming Types of algorithms Longest common subsequence : Dynamic programming GCD and LCM External Sorting - How do you sort a million 32-bit integers in 2MB RAM? maximum index of an array Missing integers print combinations Trie examples Scrabble algorithm Permutations and Combinations of string Tries Find the distinct words from a text file superstring DFS and BFS on trees, with and without recurssion Remove duplicates from the sorted array print all word combinations from phone number String matching Threaded binary tree Find the median in a continous stream of numbers Quick sort Binary search on Array - Recursive and iterative Given a list of n numbers from 1 to n-1, with one of the numbers repeated. Devise a method to determine which number is repeated Efficient code for extracting unique elements from a sorted list of array

You have two very large binary trees: T1, with millions of nodes, and T2, with hundreds of nodes Create an algorithm to decide if T2 is a subtree of T1 Minimum Spanning tree MST AVL Tree Index AVL Tree Index Splay trees Topological Sorting Red Black Tree – Insertion Red Black Tree – Deletion AVL Tree : Deleting a node from AVL Tree AVL Tree : Rotations Andersson Trees Search trees AVL Trees : Inserting a new Item Convert Binary tree to double linked list in inorder traversal print the sum( inclusive of the root ) of sub-tree rooted at each node in in-order in Binary Tree What does flattening list of items into tree means B + tree B-tree BTree in java Red Black tree Iterative or Non recursive Inorder traversal on tree DFS (Depth First Search) on tree or graph BFS (Breadth first search ) OR Level Order Traversal on tree Check if Tree is a Balanced Tree Print a Binary Tree in Zig Zag Level Order or spiral order Find Diameter of Binary Tree Find Diameter of Binary Tree Duplicate removal in Binary Search Tree Given a binary tree, print the sum( inclusive of the root ) of sub-tree rooted at each node in in-order Given a binary tree, print the sum( inclusive of the root ) of sub-tree rooted at each node in in-order Find nth largest value in a BST Find nth largest value in a BST Balanced Search tree AVL tree : Introduction What is BST or Binary Search tree? Interview Questions on Binary Search tree BST : Improving search by using sentinel Nth node in inorder traversal IsBST : Check whether the tree provided is BST or not Count binary search trees–Given N nodes, how many structurally BST are possible? Check whether binary tree are same or not? Double the tree such that insert new duplicate node for each node using cpp Given a BST, create a mirror of it. Given Binary Tree and sum, give root to leaf path such that all nodes add to that sum Print binary search tree in increasing order Print binary search tree in increasing order Find the minimum data value find in Binary Search tree (using cpp) Compute Maximum Depth or Height of binary search tree Getting the size of Binary Search Tree Create Copy of a tree (cpp) AA - tree implementation in java Anagram Trees : Part 2 DFS and BFS on trees, with and without recurssion Some cardinals Tree BST - Index Threaded binary tree Construct a tree given its inorder and preorder traversal strings. Similarly construct a tree given its inorder and post order traversal strings. Given an expression tree, evaluate the expression and obtain a paranthesized form of the expression. First / Lowest common ancestor (LCA) of 2 node in binary tree Pre Order traversal - Recursive and Iterative solution tree1.h fully updated Deleting a node from a Binary Search Tree Inorder successor OR Predecessor of BST node Implementing BST in C ( header file )

Given a BST with 2 nodes swapped, fix it Given a binary search tree with 2 nodes swapped find number of pairs not following BST properties Given the post order array find if tree is BST Sorted Linked List to Balanced BST Convert sorted array to Balanced BST Create linked lists of all the nodes at each depth for a BST Binary Tree Level-Order Traversal Using Depth First Search (DFS) [Not to USE BFS] Binary Tree Post-Order Traversal - Recursive and Iterative Solution Find the rank w.r.t K - Number of nodes with value less than K Balanced Binary Search Tree Index GetMin and GetMax in BST Binary tree - Types and Properties What is a Complete Binary Tree? Binary tree traversal: Preorder, Inorder, Post-order, BFS, DFS, Level Order, zig zag order Construct a full binary tree from a pre-order list of marked nodes Convert Binary tree to double linked list in inorder traversal Convert Binary Tree to Double Linked List in Zig-Zag Order Difference Between Sums of Odd and Even Levels in Binary Trees print the sum( inclusive of the root ) of sub-tree rooted at each node in in-order in Binary Tree What does flattening list of items into tree means Red Black tree Iterative or Non recursive Inorder traversal on tree DFS (Depth First Search) on tree or graph BFS (Breadth first search ) OR Level Order Traversal on tree Check if Tree is a Balanced Tree Print a Binary Tree in Zig Zag Level Order or spiral order Find Diameter of Binary Tree Find Diameter of Binary Tree Vertical Sum of a Binary Tree Vertical Sum of a Binary Tree Duplicate removal in Binary Search Tree Find nth largest value in a BST Find nth largest value in a BST What is BST or Binary Search tree? Interview Questions on Binary Search tree BST : Improving search by using sentinel Nth node in inorder traversal IsBST : Check whether the tree provided is BST or not Count binary search trees–Given N nodes, how many structurally BST are possible? Check whether binary tree are same or not? Double the tree such that insert new duplicate node for each node using cpp Given a BST, create a mirror of it. Given Binary Tree and sum, give root to leaf path such that all nodes add to that sum Print binary search tree in increasing order Print binary search tree in increasing order Find the minimum data value find in Binary Search tree (using cpp) Compute Maximum Depth or Height of binary search tree Getting the size of Binary Search Tree Create Copy of a tree (cpp) Important ds question DFS and BFS on trees, with and without recurssion BST - Index Threaded binary tree Construct a tree given its inorder and preorder traversal strings. Similarly construct a tree given its inorder and post order traversal strings. Given an expression tree, evaluate the expression and obtain a paranthesized form of the expression. First / Lowest common ancestor (LCA) of 2 node in binary tree Pre Order traversal - Recursive and Iterative solution Find the median in a continous stream of numbers tree1.h fully updated Deleting a node from a Binary Search Tree Inorder successor OR Predecessor of BST node Implementing BST in C ( header file )

Given a BST with 2 nodes swapped, fix it Given a binary search tree with 2 nodes swapped find number of pairs not following BST properties Given the post order array find if tree is BST Sorted Linked List to Balanced BST Convert sorted array to Balanced BST Create linked lists of all the nodes at each depth for a BST Binary Tree Level-Order Traversal Using Depth First Search (DFS) [Not to USE BFS] Binary Tree Post-Order Traversal - Recursive and Iterative Solution Find the rank w.r.t K - Number of nodes with value less than K Balanced Binary Search Tree Index GetMin and GetMax in BST Binary tree - Types and Properties What is a Complete Binary Tree? Binary tree traversal: Preorder, Inorder, Post-order, BFS, DFS, Level Order, zig zag order Construct a full binary tree from a pre-order list of marked nodes Convert Binary tree to double linked list in inorder traversal Convert Binary Tree to Double Linked List in Zig-Zag Order Difference Between Sums of Odd and Even Levels in Binary Trees print the sum( inclusive of the root ) of sub-tree rooted at each node in in-order in Binary Tree What does flattening list of items into tree means Red Black tree Iterative or Non recursive Inorder traversal on tree DFS (Depth First Search) on tree or graph BFS (Breadth first search ) OR Level Order Traversal on tree Check if Tree is a Balanced Tree Print a Binary Tree in Zig Zag Level Order or spiral order Find Diameter of Binary Tree Find Diameter of Binary Tree Vertical Sum of a Binary Tree Vertical Sum of a Binary Tree Duplicate removal in Binary Search Tree Find nth largest value in a BST Find nth largest value in a BST What is BST or Binary Search tree? Interview Questions on Binary Search tree BST : Improving search by using sentinel Nth node in inorder traversal IsBST : Check whether the tree provided is BST or not Count binary search trees–Given N nodes, how many structurally BST are possible? Check whether binary tree are same or not? Double the tree such that insert new duplicate node for each node using cpp Given a BST, create a mirror of it. Given Binary Tree and sum, give root to leaf path such that all nodes add to that sum Print binary search tree in increasing order Print binary search tree in increasing order Find the minimum data value find in Binary Search tree (using cpp) Compute Maximum Depth or Height of binary search tree Getting the size of Binary Search Tree Create Copy of a tree (cpp) Important ds question DFS and BFS on trees, with and without recurssion BST - Index Threaded binary tree Construct a tree given its inorder and preorder traversal strings. Similarly construct a tree given its inorder and post order traversal strings. Given an expression tree, evaluate the expression and obtain a paranthesized form of the expression. First / Lowest common ancestor (LCA) of 2 node in binary tree Pre Order traversal - Recursive and Iterative solution Find the median in a continous stream of numbers tree1.h fully updated Deleting a node from a Binary Search Tree Inorder successor OR Predecessor of BST node Implementing BST in C ( header file )

Convert String to ZigZag Bottom Up Given two strings str1 and str2, write code to find out if all non-unique elements in str2 are in str1? Given an array filled with char elements, find the max length of continuous white space A Needle in the Haystack Get Sentence from raw text Get Sentence from raw text Determine if a string has all unique characters Print letters followed by their frequency (Run Length Encoding) Remove duplicate characters in a string Find first non repeating character in a string Reverse a c-style string Eliminate the pairs (two same chars adjacent to each other) in string Move the Spaces to Front of the String Replace all spaces in a string with “%20″ in c-style string Given a dictionary of word - Group all words into set of anagrams of each other Boyer Moore Algorithm String Searching Algorithm - Knuth Morris Pratt or KMP Algorithm Check if 2 strings are rotated versions of each other Escape all % characters in a string; % is the escape character Remove whitespace from a string in-place, in linear time Remove whitespace from a string in-place, in linear time Implementing strcpy Implementing strcat Implementing strcmp First non repeating element in the array Find anagrams in the array of Strings Implementing a strstr() / indexOf function Combination of all the possible characters in the string Concatenate N strings with good optimization Some Stack Question Reverse a String using bits Karp-Rabin algorithm Find first occurrence of a string in another atoi() in Java itoa() in Java Find the smallest window in a string containing all characters of another string Squeeze all multiple spaces in a string into one space To find the longest substring with unique characters in a given string Reverse the words in a sentence in place Check if singly linked list is Palindrome Compare two string literals Anagram Checker–To check if 2 strings are anagrams Anagram Checker–To check if 2 strings are anagrams All permutations of a string All permutations of a string Anagram Trees : Part 2 Secure permutations with block ciphers Longest common substring revisited C Strings Reducing the space for LCS lengths Hirschberg’s linear space algorithm in C++ Hirschberg's algorithm Dynamic Programming Algorithm (DPA) for Edit-Distance Longest common substring problem Longest common subsequence : Dynamic programming String matching Given a string s1 and a string s2, write a snippet to say whether s2 is a rotation of s1 using only one call to strstr routine? (eg given s1 = ABCD and s2 = CDAB, return true, given s1 = ABCD, and s2 = ACBD , return false) WAP to check whether string is palindrome Given two strings A and B, how would you find out if the characters in B were a subset of the characters in A? String Class in cpp(Standard cpp strings) Miscellaneous cases with printf Making a String class in cpp

Given an array arr[], find the maximum j – i such that arr[j] > arr[i] Given an array arr[], find the maximum j – i such that arr[j] > arr[i] Deterministic Selection - Select the i th smallest element Sorting 10 GB file of integer with limited ram. Sorting a 2GB file with one string per line Sort an array of strings so that anagrams are next to each other Merge two sorted arrays - One having big enough buffer to hold another Merge Overlapping Intervals Given an array of 100,000 pixel color values and each of which is an integer in the range (0,255). Give sorting algorithm. Insertion sort on linked list Selection sort on linked list Sort a linked list using bubble sort Sort a linked list using quick sort Bubble sort on double linked list Sort a linked list using merge sort What's the fastest algorithm for sorting a linked list? Merge two arrays efficiently - one sorted, another unsorted Sorting implementation in c Bottom-up Merge Sort k-way merge - Merging k sorted arrays of n elements Sorting Topological Sorting Randomized Selection : Selecting the i'th smallest element What is a sorting algorithm? Insertion sort Selection Sort What is Bucket Sort? Bitonic Sort Bidirectional Bubble Sort Priority Queue based on Sorted Linked Lists Sorting in Hungarian Way 2 Sum Problem : Given an integer array and a number T, find all unique pairs of (a, b) whose sum is equal to T 2 Sum Problem : Given an integer array and a number T, find all unique pairs of (a, b) whose sum is equal to T Sorted Linear Hash Table Sorting Array of Three Kinds or The Dutch National Flag Problem OR three color sort Heap Sort in java Searching the element in sorted infinite array of integers DFS (Depth First Search) on tree or graph Sorting a very large file which cannot fit in memory Counting sort Sorting a Stack using push,pop,isEmpty and peek Given two sorted arrays of size m and n respectively (m >> n), how to merge them together? Using stl sort Comparison sort and Integer sorts Important ds question External Sorting - How do you sort a million 32-bit integers in 2MB RAM? Sorting binary array - Array containing only 0 and 1 in one pass OR two color sort Sorting binary array - Array containing only 0 and 1 in one pass OR two color sort Remove duplicates from a sorted linked list Bubble sort Quick sort Radix sort Merge Sort

Lego Blocks Problem Maximize the number of magical gems by passing through array of house Number of steps required to convert string 1 to string2 when only bring character to first index operation is giving Implement a function similar to diff command in linux Maximum single sell profit from stock Find the largest subarray with sum of 0 in the given array Maximum subset of Cuboid boxes that can fit into one another Given a set of numbers [1-N]. Subsets such that the sum of numbers in the subset is a prime number. Petrol Bunk in a Circle. Get Sentence from raw text Get Sentence from raw text Suggest the selling time and buying time of a share based on stock price prediction Maximum product sub-array Circus tower sorting problem Print all combinations of n balanced parentheses Two egg puzzle Avid TV watcher Maximum weight independent set (WIS) graph problem using DP Bellman ford algorithm - One source shortest path Maximum continuous sum subarray problem Maximum continuous sum subarray problem Huffman Codes Print pascal's triangle Convert array of positive numbers to sorted array Minimum number of coins to get particular amount, given multiple denomination Get maximum sum from coins in a line Find optimal number of jumps to reach last element Max possible sum of non-consecutive elements Max possible sum of non-consecutive elements Maximum size square sub-matrix with all 1s Longest increasing subsequence To find the longest substring with unique characters in a given string Find longest palindrome in a string. Find longest palindrome in a string. Longest common substring revisited Reducing the space for LCS lengths Hirschberg’s linear space algorithm in C++ Hirschberg's algorithm Dynamic Programming Algorithm (DPA) for Edit-Distance Dynamic Programming Practise Problem Set 3 Longest common substring problem Dynamic Programming Practise Problem Set 2 Matrix chain multiplication Dynamic Programming Practise Problem Set 1 Dynamic-Programming Algorithm for the Activity-Selection Problem Dynamic-Programming Solution to the 0-1 Knapsack Problem Find the nth Fibonacci number Optimal Substructure Overlapping subproblems in Dynamic programming Common characterstics in dynamic programming Introduction to Dynamic programming Longest common subsequence : Dynamic programming

Lego Blocks Problem Maximize the number of magical gems by passing through array of house Number of steps required to convert string 1 to string2 when only bring character to first index operation is giving Implement a function similar to diff command in linux Maximum single sell profit from stock Find the largest subarray with sum of 0 in the given array Maximum subset of Cuboid boxes that can fit into one another Given a set of numbers [1-N]. Subsets such that the sum of numbers in the subset is a prime number. Petrol Bunk in a Circle. Get Sentence from raw text Get Sentence from raw text Suggest the selling time and buying time of a share based on stock price prediction Maximum product sub-array Circus tower sorting problem Print all combinations of n balanced parentheses Two egg puzzle Avid TV watcher Maximum weight independent set (WIS) graph problem using DP Bellman ford algorithm - One source shortest path Maximum continuous sum subarray problem Maximum continuous sum subarray problem Huffman Codes Print pascal's triangle Convert array of positive numbers to sorted array Minimum number of coins to get particular amount, given multiple denomination Get maximum sum from coins in a line Find optimal number of jumps to reach last element Max possible sum of non-consecutive elements Max possible sum of non-consecutive elements Maximum size square sub-matrix with all 1s Longest increasing subsequence To find the longest substring with unique characters in a given string Find longest palindrome in a string. Find longest palindrome in a string. Longest common substring revisited Reducing the space for LCS lengths Hirschberg’s linear space algorithm in C++ Hirschberg's algorithm Dynamic Programming Algorithm (DPA) for Edit-Distance Dynamic Programming Practise Problem Set 3 Longest common substring problem Dynamic Programming Practise Problem Set 2 Matrix chain multiplication Dynamic Programming Practise Problem Set 1 Dynamic-Programming Algorithm for the Activity-Selection Problem Dynamic-Programming Solution to the 0-1 Knapsack Problem Find the nth Fibonacci number Optimal Substructure Overlapping subproblems in Dynamic programming Common characterstics in dynamic programming Introduction to Dynamic programming Longest common subsequence : Dynamic programming

Skiplists Suffix Array Skiplist - TOC Symbol table data structure Deterministic Selection - Select the i th smallest element Find all pairs (x, y) in a sorted array so that x + y < z Implement a stack using queue Implement a stack using 2 queues Algorithm Introduction Find next higher number using exact same digits Iterators - Allowing iteration over data structures (in java) Evaluating postfix expression using stack Array Implementation of Heap Array Implementation of Heap Cuts of Graphs Data Type in Data Structure Hash Tables Closest Pair Algorithm Randomized Selection : Selecting the i'th smallest element Meaning behind Master Method Master Method for Solving Recurrences Strassen's Subcubic Matrix Multiplication Algorithm Inversions Operation time complexity for a LINKED LIST Operation time complexity for an ARRAY Time complexity - Omega of algorithms Time complexity of algorithms - In particular Big Omega of algorithms String Searching Algorithm - Knuth Morris Pratt or KMP Algorithm Priority Queue What is a non-linear datastructure? What is a linear datastructure? What is a sorting algorithm? Introduction to Heap Selection Sort What is Bucket Sort? What is a Graph data structure? Graph Traversal Methods What is a Complete Binary Tree? Data Structure Introduction Link list ADT Bubble sort Quick sort

Smart pointer in C++ Take a pointer to a Node structure as a parameter and return a complete copy of the passed-in data structure Destructor in base class needed to be virtual in C++ “volatile” keyword in C (and Java) Deep copy and shallow copy in C++ Virtual functions in C++ Compare and contrast a hash table vs. an STL map Print the last K lines of a file using C++ Selection Sort Bloom filters Printing "Hello World" to screen without using a single semicolon in C/C++ Printing "Hello World" to screen without using a single semicolon in C/C++ Squeeze all multiple spaces in a string into one space Leveling sectors in a circle What is BST or Binary Search tree? Common naming convention : Coding Style Java and CPP - the differences and similarities Enum in c++ How to bound check arrays in cpp / c File IO in c++ 1 Using == operator in better way in cpp Pointer cause decay, references do not. References and Constants Writing a DLL in C++ C++ STL: Iterators and Containers ‘exit’ was not declared in this scope how to chk if a no. is integer or not. Bubble sort Stack implementation using linked list File handling in cpp Operator Precedence in C & CPP How does throwing and catching exceptions differ from using setjmp and longjmp? Stack ADT Miscellaneous cases with printf Strings Access in cpp classes C preprocessor Complicated Declaration Making a String class in cpp Program to Add two polynomials Representing Arrays as a class in cpp

Print all sequences of given length Get Sentence from raw text Get Sentence from raw text The Celebrity Problem Eight Queen Puzzle (likewise N Queen) Number of ways of representing n cents using quarters, dimes, nickels and pennies Implement the “paint fill” function Print all combinations of n balanced parentheses All possible paths for a robot moving along a NxN grid Two egg puzzle Unique Paths in 2D grid How many possible ways the child can run up the ladder Find Nth largest element in the rotated sorted array Find Nth largest element in the rotated sorted array Find the rotation count in rotated sorted array Tower of Hanoi Problem Strassen's Subcubic Matrix Multiplication Algorithm Find all subsets of a given set OR Find power set of a given set Find all subsets of a given set OR Find power set of a given set print the sum( inclusive of the root ) of sub-tree rooted at each node in in-order in Binary Tree Print pascal's triangle BFS (Breadth first search ) OR Level Order Traversal on tree Find the minimum element in the rotated sorted sorted array Find the minimum element in the rotated sorted sorted array Search an element in the sorted rotated array Print a Binary Tree in Zig Zag Level Order or spiral order XML Sequence Delimiter All permutations of a string All permutations of a string Given a BST, create a mirror of it. Getting the size of Binary Search Tree Find the nth Fibonacci number GCD and LCM Merge Sort Convert integer into a binary number Binary search on Array - Recursive and iterative Euclid's Algorithm : GCD of 2 integers Reversing a number How to add two numbers without using the plus operator? Calculate pow function

Find the maximum (or minimum) of two numbers (or morenumbers) without use of comparison operators or if-else Find the nearest numbers that have same number of 1s for an integer Swap odd and even bits in an integer Find missing integer in an array with only access to jth bit of element A[i] Division without using *, / or % (Divide Two Integers) Count total set bits in all numbers from 1 to n Next Power of 2 Count number of bits to be flipped to convert A to B Some useful resources Explain ((n & (n-1)) == 0) Print binary representation of a decimal number Print binary representation of a decimal number Set all bits of a number in a range equal to another number Divide a number by 3 without using *, /, +, -, % operators Add two numbers without using arithmetic operators Divide a number by 3 without using any of operators (%,/,*) Add 1 to a given number without arithmetic operators Find Position of the only Set Bit Checking if a bit is on or off without affecting other bits Toggle a specified bit in a bit string without effecting other bits Divide a number by a power of two using bit right shift Multiply a number by a power of two using bit left shift Turning a bit off without affecting other bits Bit Manipulation Tips and Tricks Finding an integer that repeats odd number of times in an array of positive integers Check If an Integer's Bit Representation Is a Palindrome Implement Add,Subtract,Multiplication,Division Using Bit Manipulation Reverse a String using bits Give a fast way to multiply a number by 7 To reverse the bits in an integer Check if the 20th bit of a 32 bit integer is on or off? Count bits set in an integer Using pointers to break into bytes To swap the two nibbles in a byte Code to check if an integer is a power of 2 or not in a single line How to add two numbers without using the plus operator? How to find out if a machine is 32 bit or 64 bit? To determine whether machine is Little-Endian and Big-Endian? Swap two number in place without temporary variables.

Data structure and algorithm interview question for java programmers Memory requirement of a program in java Count the number of calls of put() and get() for a map in Java Object reflection in Java final, finally and finalize in Java Finally block and return statement Private constructor in Java “volatile” keyword in C (and Java) Find the kth number with prime factors 3, 5 and 7 Determine whether two lines would intersect on a Cartesian plane Number of unique elements in sorted array with repeated elements Data Structure to Emulate LRU Cache Iterators - Allowing iteration over data structures (in java) Generic data structures in java Adjacency list represention of graph in Java Selection Sort Search an element in the sorted rotated array atoi() in Java XML Sequence Delimiter Counting sort All permutations of a string All permutations of a string Program to check if two rectangle overlap or itntersect Program to check if two rectangle overlap or itntersect Array implementation of stack Array implementation of stack Enums in java Modifying Java Variables (w.r.t c and c++) Constructor in java 1 Common naming convention : Coding Style Improving coding style into classes Improving coding style into functions or methods Java specific naming convention Specific cases of naming enhancing naming style Java and CPP - the differences and similarities Bubble sort Stack implementation using linked list

K reverse a linked list with increasing K Union and Intersection of two unsorted Linked Lists Priority Queue based on Sorted Linked Lists Removing a loop in a singly linked list Concurrent Skip List Find common nodes from two linked lists using recursion Y – shaped Linked List. Algorithm to find the node of intersection of two lists. Remove duplicates from an unsorted linked list K – Reverse a linked list Deleting a node from a singly linked link list Link list ADT Calculate length of the linked list that contains loop Add 2 large numbers in the form of list, without reversing the linked lists Finding the Start of a Loop in a Linked List Finding the Start of a Loop in a Linked List Deleting a node in singly linked list if it is less than any of the successor nodes Deleting a node in singly linked list if it is less than any of the successor nodes Check if singly linked list is Palindrome Sum of two long positive numbers (each represented by linked lists) Find median of a linked list or a Tree Intersection of two sorted lists or 2 sorted arrays Deleting a middle node from a single linked list when pointer to the previous node is not available Reverse a linked list Remove duplicates from a sorted linked list Insert nodes into a linked list in a sorted fashion Return the nth node from the end of a linked list Binary search on a linked list C program to free the nodes of a linked list Copy of a linked list Compare two linked lists Middle of a linked list Basic functions of link list - Add and print Detecting a loop in a linked list To add two long positive numbers (each represented by linked lists in C)

“volatile” keyword in C (and Java) Selection Sort Using == operator in better way in cpp Self reproducing program in C zero sized allocation using malloc return and exit from main: difference How to create function polymorphism in C C Strings Finding time of execution of code in c Bubble sort Give a fast way to multiply a number by 7 Reversing a number To reverse the bits in an integer Check if the 20th bit of a 32 bit integer is on or off? Count bits set in an integer File Handling in c Syntax in C What is a dangling pointer? What are reference counters with respect to pointers? How to find out if a machine is 32 bit or 64 bit? Operator Precedence in C & CPP Going beyond range of datatype Extern keyword Using ## and # with define. Return values of some functions in c The preprocessor directives can be redefined anywhere in the program What is the difference between goto and longjmp() and setjmp()? Given only putchar (no sprintf, itoa, etc.) write a routine putlong that prints out an unsigned long in decimal Some macros Using define without assigning value Stack ADT I/O in c without printf and scanf. C preprocessor Complicated Declaration

Priority Queue Bloom filters ArrayDeque + Stack Algorithms Search trees Some Stack Question Advantage and disadvantage of datastructures Sorting a Stack using push,pop,isEmpty and peek What is a data structure? C++ STL: Iterators and Containers Important ds question Tries DFS and BFS on trees, with and without recurssion Some cardinals Tree BST - Index Construct a tree given its inorder and preorder traversal strings. Similarly construct a tree given its inorder and post order traversal strings. Given an expression tree, evaluate the expression and obtain a paranthesized form of the expression. First / Lowest common ancestor (LCA) of 2 node in binary tree Pre Order traversal - Recursive and Iterative solution Circular Queue Bubble sort Stack implementation using linked list Radix sort Merge Sort Data Structures Interview Questions (Theoritical) Given a list of n numbers from 1 to n-1, with one of the numbers repeated. Devise a method to determine which number is repeated Efficient code for extracting unique elements from a sorted list of array tree1.h fully updated Deleting a node from a Binary Search Tree Inorder successor OR Predecessor of BST node Implementing BST in C ( header file ) Stack ADT Representing Arrays as a class in cpp

Priority Queue Bloom filters ArrayDeque + Stack Algorithms Search trees Some Stack Question Advantage and disadvantage of datastructures Sorting a Stack using push,pop,isEmpty and peek What is a data structure? C++ STL: Iterators and Containers Important ds question Tries DFS and BFS on trees, with and without recurssion Some cardinals Tree BST - Index Construct a tree given its inorder and preorder traversal strings. Similarly construct a tree given its inorder and post order traversal strings. Given an expression tree, evaluate the expression and obtain a paranthesized form of the expression. First / Lowest common ancestor (LCA) of 2 node in binary tree Pre Order traversal - Recursive and Iterative solution Circular Queue Bubble sort Stack implementation using linked list Radix sort Merge Sort Data Structures Interview Questions (Theoritical) Given a list of n numbers from 1 to n-1, with one of the numbers repeated. Devise a method to determine which number is repeated Efficient code for extracting unique elements from a sorted list of array tree1.h fully updated Deleting a node from a Binary Search Tree Inorder successor OR Predecessor of BST node Implementing BST in C ( header file ) Stack ADT Representing Arrays as a class in cpp

K reverse a linked list with increasing K Rearranging linked list first odd next even numbers Concurrent Skip List Find common nodes from two linked lists using recursion Y – shaped Linked List. Algorithm to find the node of intersection of two lists. Remove duplicates from an unsorted linked list K – Reverse a linked list Deleting a node from a singly linked link list Link list ADT Calculate length of the linked list that contains loop Add 2 large numbers in the form of list, without reversing the linked lists Finding the Start of a Loop in a Linked List Finding the Start of a Loop in a Linked List Deleting a node in singly linked list if it is less than any of the successor nodes Deleting a node in singly linked list if it is less than any of the successor nodes Check if singly linked list is Palindrome Sum of two long positive numbers (each represented by linked lists) Find median of a linked list or a Tree Intersection of two sorted lists or 2 sorted arrays Deleting a middle node from a single linked list when pointer to the previous node is not available Reverse a linked list Remove duplicates from a sorted linked list Insert nodes into a linked list in a sorted fashion Return the nth node from the end of a linked list Binary search on a linked list C program to free the nodes of a linked list Copy of a linked list Compare two linked lists Middle of a linked list Basic functions of link list - Add and print Detecting a loop in a linked list Stack implementation using linked list To add two long positive numbers (each represented by linked lists in C)

Given the push and pop sequence on stack, verify if corresponding sequence is correct or not Solve Towers of Hanoi using stack The Celebrity Problem Implement a stack using queue Implement a stack using 2 queues Stack with find-min/find-max in O(1) time Stack of plates Implementing 2 stacks in an array Maximum value in a Sliding Window Generic data structures in java Evaluating postfix expression using stack Converting an Infix Expression to Postfix expression using a stack Checking whether the paranthesis are balanced in the expression Resizing Array implementation of stack Circular Stack ArrayDeque + Stack Algorithms Maximum Area Rectangle in Histogram Some Stack Question Implement 3 stacks in 1 array Implement a queue in which push_rear(), pop_front() and get_min() are all constant time operations. Add 2 large numbers in the form of list, without reversing the linked lists Stack DS to implement constant time Minimum element lookup How to reverse a stack in place ? Use some Datastructure to get O(1) stack operations Sorting a Stack using push,pop,isEmpty and peek Implement a Queue using two stacks Array implementation of stack Array implementation of stack The stack and the heap Write a C Program to reverse a stack "in place" using recursion ? Stack implementation using linked list Program to check if the stack grows up or down Stack ADT

Searching Questions Find the duplicate element most number of times in array of 0 to n-1 Find duplicate elements in the array with 4KB memory only Check if array contains duplicates Find duplicates in the ranged array Find the two repeating elements in ranged array Find the two non-repeating elements in a ranged array of repeating elements Remove duplicates from unsorted array Number of unique elements in sorted array with repeated elements Find the maximum repeating number in array where all the elements are in range 0 to k-1, k ∈ [0,N] Finding the max repeated element in an array Remove duplicate characters in a string Find first non repeating character in a string Finding an integer that repeats odd number of times in an array of positive integers Find the First Duplicated Integer in an Array containing numbers from 1 to N Without Using Extra Memory Find the First Duplicated Integer in an Array containing numbers from 1 to N Without Using Extra Memory Remove duplicates from an unsorted linked list First non repeating element in the array Majority element in the array One duplicate , one missing element in an array Given numbers from 1 to N+1, with number being from 1 and N and one of the number being repeatative. Find the repeating element. Duplicate removal in Binary Search Tree Double the tree such that insert new duplicate node for each node using cpp Remove duplicates from the sorted array Remove duplicates from a sorted linked list Given an array of n integers from 1 to n with one integer repeated twice

Given a node in binary tree - Check if left and right subtree are mirror of each other Given two strings str1 and str2, write code to find out if all non-unique elements in str2 are in str1? Given a binary tree with extra field "next pointer" in node, populate the next pointer to the nodes inorder successor Amazon Questions - Set 1 Replace all spaces in a string with “%20″ in c-style string Find largest Binary Search Tree in a Binary Tree Convert Binary tree to Binary Search Tree conversion in place Write code to find nth largest number from a stream of numbers. Given a stream of characters, find the kth non-repeated character at any given time. Given a stream of characters, find the kth non-repeated character at any given time. Find all the pythagorean triplets in an array of integer Maximum value in a Sliding Window Given a dictionary of word - Group all words into set of anagrams of each other Rearranging linked list first odd next even numbers K – Reverse a linked list Find the point of transition from 0 to 1 in an infinite sorted array containings only 0 and 1 . Find the point of transition from 0 to 1 in an infinite sorted array containings only 0 and 1 . Minimum number of coins to get particular amount, given multiple denomination Search an element in the sorted rotated array Longest increasing subsequence Vertical Sum of a Binary Tree Vertical Sum of a Binary Tree Median of 2 sorted arrays of equal size n Median of 2 sorted arrays of equal size n Important ds question

Find Diameter of Binary Tree Find Diameter of Binary Tree Row consisting max continuous chain of 1’s in an n * n grid Leveling sectors in a circle Reverse the words in a sentence in place Find nth largest value in a BST Find nth largest value in a BST Sorting a Stack using push,pop,isEmpty and peek Interview Questions on Binary Search tree Why is manhole cover circular? Solve the Rat In A Maze problem using backtracking. Sorting binary array - Array containing only 0 and 1 in one pass OR two color sort Sorting binary array - Array containing only 0 and 1 in one pass OR two color sort Data Structures Interview Questions (Theoritical) To reverse the bits in an integer Check if the 20th bit of a 32 bit integer is on or off? CTS Aptitude Question paper(Yellow) CTS Aptitude Question paper(Yellow) CTS Aptitude Question paper(Yellow) Questions on various topics Acronyms used in operating system Besides communication cost, what is the other source of inefficiency in RPC? Some macros Using define without assigning value

Transform one word into another by changing only one letter at a time The Celebrity Problem Find if there is a path between two vertices in a directed graph Find if there is a path between two vertices in a directed graph Maximum weight independent set (WIS) graph problem using DP BFS (Breadth first search) on Graph DFS (Depth first search) for graph Dijkstra's algorithm for equal weight edges using BFS Random Contraction Algorithm Graph Representations Cuts of Graphs Strongly Connected Graph Topological Sorting Minimum Cut Problem BFS and Undirected Connectivity Dijkstra's Shortest Path Algorithm Adjacency list represention of graph in Java Graph Search Introduction What is a Graph data structure? DFS (Depth First Search) on tree or graph BFS (Breadth first search ) OR Level Order Traversal on tree Prim's Algorithm Kruskal's Algorithm

Point inside a triangle or NOT Triangle Formation Find the average of n numbers Fill a magic square of size n, n being odd CTRL+A, CTRL+C, CTRL+V CTRL+A, CTRL+C, CTRL+V Guess the solution of selecting 4 balls from set of 4 different colors Point inside a rectangle or not Given a number x, less than 100. How will you generate true with probability x/100. Given a number 123456789, two opearators + and *, value k , find all the such expressions that evaluates to the given value k Form a circle from 3 points How many time function gets called? Polite Numbers - Calculate all the ways such that a number can be written as sum of 2 or more consecutive numbers Find average of a stream of the numbers Print all sequences of given length Number of Subsets without consecutive elements Match two board configurations of tic-tac-toe problem Find next higher number using exact same digits Convert a Number (unknown base) to a Base 10 Number Euclid's Algorithm : GCD of 2 integers Bresenham's circle algorithm Routine to draw a circle (x ** 2 + y ** 2 = r ** 2) without making use of any floating point computations at all. Calculate pow function

Find the appropriate data structure Convert sorted array to Balanced BST Red Black Tree vs AVL Tree vs B-Tree Balanced Binary Search Tree Index AVL Tree Index AVL Tree Index Splay trees Red Black Tree – Insertion Red Black Tree – Deletion AVL Tree : Deleting a node from AVL Tree AVL Tree : Rotations Andersson Trees Search trees AVL Trees : Inserting a new Item B + tree B-tree BTree in java Red Black tree Check if Tree is a Balanced Tree Balanced Search tree AVL tree : Introduction

For a Given node of a binary tree, print the K distance nodes. Print all nodes that are at distance k from a leaf node Find the distance between 2 nodes in Binary Tree Find the distance between 2 nodes in Binary Tree Program to count leaf nodes in a binary tree Convert Binary Tree to Doubly linked list in level order Foldable Binary Trees - Given a binary tree, find out if the tree can be folded or not. Given a node in binary tree - Check if left and right subtree are mirror of each other Check if 2 trees are iso-morphic Print all paths in a binary tree which sum up to a value Determine if a small tree T2 is the subtree of a huge tree T1 Given a binary tree with extra field "next pointer" in node, populate the next pointer to the nodes inorder successor Print nodes at k distance from root Binary Tree In-Order Traversal - Recursive and Iterative Solution Binary tree - Types and Properties What is a Complete Binary Tree? Binary tree traversal: Preorder, Inorder, Post-order, BFS, DFS, Level Order, zig zag order Print a Binary Tree in Zig Zag Level Order or spiral order Vertical Sum of a Binary Tree Vertical Sum of a Binary Tree Balanced Search tree

For a Given node of a binary tree, print the K distance nodes. Print all nodes that are at distance k from a leaf node Find the distance between 2 nodes in Binary Tree Find the distance between 2 nodes in Binary Tree Program to count leaf nodes in a binary tree Convert Binary Tree to Doubly linked list in level order Foldable Binary Trees - Given a binary tree, find out if the tree can be folded or not. Given a node in binary tree - Check if left and right subtree are mirror of each other Check if 2 trees are iso-morphic Print all paths in a binary tree which sum up to a value Determine if a small tree T2 is the subtree of a huge tree T1 Given a binary tree with extra field "next pointer" in node, populate the next pointer to the nodes inorder successor Print nodes at k distance from root Binary Tree In-Order Traversal - Recursive and Iterative Solution Binary tree - Types and Properties What is a Complete Binary Tree? Binary tree traversal: Preorder, Inorder, Post-order, BFS, DFS, Level Order, zig zag order Print a Binary Tree in Zig Zag Level Order or spiral order Vertical Sum of a Binary Tree Vertical Sum of a Binary Tree Balanced Search tree

Searching Questions Find the duplicate element most number of times in array of 0 to n-1 Check if array contains duplicates Find duplicates in the ranged array Find the two repeating elements in ranged array Find the two non-repeating elements in a ranged array of repeating elements Find Nth largest element in the rotated sorted array Find Nth largest element in the rotated sorted array Linear Search on Array Finding an integer that repeats odd number of times in an array of positive integers Find the point of transition from 0 to 1 in an infinite sorted array containings only 0 and 1 . Find the point of transition from 0 to 1 in an infinite sorted array containings only 0 and 1 . Searching the element in sorted infinite array of integers DFS (Depth First Search) on tree or graph Find the minimum element in the rotated sorted sorted array Find the minimum element in the rotated sorted sorted array Trie : Searching in Trie Balanced Search tree BST : Improving search by using sentinel BK-Treesal Binary search on Array - Recursive and iterative

Merge two sorted arrays - One having big enough buffer to hold another Number of unique elements in sorted array with repeated elements Finding the biggest difference between sorted array values Sorted Linked List to Balanced BST Convert sorted array to Balanced BST Find the minimum and maximum in the array Merge two arrays efficiently - one sorted, another unsorted Given an integer array of which both first half and second half are sorted. Write a function to merge the two parts to create one single sorted array in place [do not use any extra space]. k-way merge - Merging k sorted arrays of n elements Find Nth largest element in the rotated sorted array Find Nth largest element in the rotated sorted array Find the rotation count in rotated sorted array Convert array of positive numbers to sorted array Find the minimum element in the rotated sorted sorted array Find the minimum element in the rotated sorted sorted array Search an element in the sorted rotated array Median of 2 sorted arrays of equal size n Median of 2 sorted arrays of equal size n Intersection of two sorted lists or 2 sorted arrays Remove duplicates from the sorted array

Lazy Caterer's sequence Given two strings str1 and str2, write code to find out if all non-unique elements in str2 are in str1? Data structure and algorithm interview question for java programmers Amazon Questions - Set 1 Finding an integer that repeats odd number of times in an array of positive integers Find the point of transition from 0 to 1 in an infinite sorted array containings only 0 and 1 . Find the point of transition from 0 to 1 in an infinite sorted array containings only 0 and 1 . Longest increasing subsequence Vertical Sum of a Binary Tree Vertical Sum of a Binary Tree Majority element in the array Spiral printing of a two dimensional array All permutations of a string All permutations of a string Sorting binary array - Array containing only 0 and 1 in one pass OR two color sort Sorting binary array - Array containing only 0 and 1 in one pass OR two color sort Given an array of n integers from 1 to n with one integer repeated twice Routine to draw a circle (x ** 2 + y ** 2 = r ** 2) without making use of any floating point computations at all. Given two strings A and B, how would you find out if the characters in B were a subset of the characters in A?

Bubble sort Array of 0 and 1, put 0's at even position and 1's at odd position Anagram program implentation Finding whether 2 arrays are intersecting Given an array of n integers from 1 to n with one integer repeated twice Given a list of n numbers from 1 to n-1, with one of the numbers repeated. Devise a method to determine which number is repeated Give a fast way to multiply a number by 7 Routine to draw a circle (x ** 2 + y ** 2 = r ** 2) without making use of any floating point computations at all. c program without main How can we sum the digits of a given number in single statement? A program to print numbers from 1 to 100 without using loops How to add two numbers without using the plus operator? Convert the decimal number to any base (binary, hex, oct etc...) How to find out if a machine is 32 bit or 64 bit? Given an eight-bit bitmap graphics file, devise an algorithm to convert the file into a two-bit ASCII approximation Given the time, devise an algorithm to calculate the angle between the hour and minute hands of an analog clock Efficient code for extracting unique elements from a sorted list of array Given only putchar (no sprintf, itoa, etc.) write a routine putlong that prints out an unsigned long in decimal Swap two number in place without temporary variables.

Convert Binary Tree to Doubly linked list in level order Number of steps required to convert string 1 to string2 when only bring character to first index operation is giving Sorted Linked List to Balanced BST Convert sorted array to Balanced BST Create linked lists of all the nodes at each depth for a BST Convert Binary tree to Binary Search Tree conversion in place Converting an Infix Expression to Postfix expression using a stack Converting integers less than 100 to words Convert Binary tree to double linked list in inorder traversal Convert integers to roman numbers Convert Binary Tree to Double Linked List in Zig-Zag Order Convert array of positive numbers to sorted array Convert a Number (unknown base) to a Base 10 Number atoi() in Java itoa() in Java Taking input as string 1 - " C-String to Int " Convert integer into a binary number Convert the decimal number to any base (binary, hex, oct etc...)

Shortest distances between two words in a file Stack with find-min/find-max in O(1) time Find the minimum and maximum in the array Find Maximum Value in the unsorted array Find kth largest in an Array find out the largest and second largest number in an array find out the largest and second largest number in an array How to find max. and min. in array using minimum comparisons? Find Nth largest element in the rotated sorted array Find Nth largest element in the rotated sorted array Find the rotation count in rotated sorted array Minimum Distance Between Two Elements in an Array Minimum number of coins to get particular amount, given multiple denomination Find the minimum element in the rotated sorted sorted array Find the minimum element in the rotated sorted sorted array Stack DS to implement constant time Minimum element lookup IsBST : Check whether the tree provided is BST or not Find the minimum data value find in Binary Search tree (using cpp)

Angular JS interview questions Skiplist - TOC Selection Algorithms Cracking the coding interview questions Trie Tutorial Searching Questions Some useful resources Strings index Find the minimum and maximum in the array Sorting implementation in c Company specific interviews Arrays Index Balanced Binary Search Tree Index Red Black Tree Index Sorting Randomized Algorithm Bit Manipulation Tips and Tricks BST - Index

Maximum single sell profit from stock Given an array filled with char elements, find the max length of continuous white space Finding the biggest difference between sorted array values Stack with find-min/find-max in O(1) time Find the minimum and maximum in the array Find Maximum Value in the unsorted array Find kth largest in an Array find out the largest and second largest number in an array find out the largest and second largest number in an array How to find max. and min. in array using minimum comparisons? Finding the max repeated element in an array Maximum value in a Sliding Window Maximum continuous sum subarray problem Maximum continuous sum subarray problem Majority element in the array IsBST : Check whether the tree provided is BST or not Compute Maximum Depth or Height of binary search tree

Binary Tree Level-Order Traversal Using Depth First Search (DFS) [Not to USE BFS] Binary tree traversal: Preorder, Inorder, Post-order, BFS, DFS, Level Order, zig zag order Construct a full binary tree from a pre-order list of marked nodes What does flattening list of items into tree means Iterative or Non recursive Inorder traversal on tree DFS (Depth First Search) on tree or graph BFS (Breadth first search ) OR Level Order Traversal on tree Given a binary tree, print the sum( inclusive of the root ) of sub-tree rooted at each node in in-order Nth node in inorder traversal Print binary search tree in increasing order Print binary search tree in increasing order DFS and BFS on trees, with and without recurssion Construct a tree given its inorder and preorder traversal strings. Similarly construct a tree given its inorder and post order traversal strings. Pre Order traversal - Recursive and Iterative solution Implementing BST in C ( header file )

How do I check if a number is a palindrome? How do I check if a number is a palindrome? Convert integers to roman numbers Convert a Number (unknown base) to a Base 10 Number itoa() in Java External Sorting - How do you sort a million 32-bit integers in 2MB RAM? Missing integers how to chk if a no. is integer or not. Euclid's Algorithm : GCD of 2 integers Given an array of n integers from 1 to n with one integer repeated twice Check if the 20th bit of a 32 bit integer is on or off? Count bits set in an integer Find all sets of consecutive integers that add up to 1000. Code to check if an integer is a power of 2 or not in a single line

Resizing Array implementation of stack DFS (Depth first search) for graph Integer Multiplication using Karatsuba algorithm Meaning behind Master Method Master Method for Solving Recurrences Dijkstra's Shortest Path Algorithm Operation time complexity for a LINKED LIST Operation time complexity for an ARRAY Time complexity of algorithms - In particular Big Omega of algorithms Heap Sort in java Majority element in the array Balanced Search tree Quick sort Basic Mathematics in Algorithms

Searching in a sorted array of strings with empty strings Find Nth largest element in the rotated sorted array Find Nth largest element in the rotated sorted array Find the point of transition from 0 to 1 in an infinite sorted array containings only 0 and 1 . Find the point of transition from 0 to 1 in an infinite sorted array containings only 0 and 1 . Searching the element in sorted infinite array of integers Find the minimum element in the rotated sorted sorted array Find the minimum element in the rotated sorted sorted array Search an element in the sorted rotated array Find an element in matrix in which rows and columns are sorted Balanced Search tree Intersection of two sorted lists or 2 sorted arrays Binary search on Array - Recursive and iterative

Given a binary search tree with 2 nodes swapped find number of pairs not following BST properties Program to count leaf nodes in a binary tree Count the number of 2s between 0 and n Count the number of digits in the number Count the number of calls of put() and get() for a map in Java Number of unique elements in sorted array with repeated elements Count total set bits in all numbers from 1 to n Count number of bits to be flipped to convert A to B Given an array of 100,000 pixel color values and each of which is an integer in the range (0,255). Give sorting algorithm. Find the rotation count in rotated sorted array Counting sort Count binary search trees–Given N nodes, how many structurally BST are possible? Count bits set in an integer

Maximum single sell profit from stock Count the number of digits in the number k-way merge - Merging k sorted arrays of n elements Integer Multiplication using Karatsuba algorithm Closest Pair Algorithm Master Method for Solving Recurrences Strassen's Subcubic Matrix Multiplication Algorithm Median of 2 sorted arrays of equal size n Median of 2 sorted arrays of equal size n Divide and Conquer Quick sort Merge Sort Binary search on Array - Recursive and iterative

Given a BST with 2 nodes swapped, fix it Given a binary search tree with 2 nodes swapped find number of pairs not following BST properties Given a binary tree with extra field "next pointer" in node, populate the next pointer to the nodes inorder successor Binary Tree In-Order Traversal - Recursive and Iterative Solution Binary tree traversal: Preorder, Inorder, Post-order, BFS, DFS, Level Order, zig zag order Given a binary tree, print the sum( inclusive of the root ) of sub-tree rooted at each node in in-order Nth node in inorder traversal Print binary search tree in increasing order Print binary search tree in increasing order Threaded binary tree Construct a tree given its inorder and preorder traversal strings. Similarly construct a tree given its inorder and post order traversal strings. Inorder successor OR Predecessor of BST node Implementing BST in C ( header file )

Union and Intersection of two unsorted Linked Lists Union and Intersection of two sorted arrays Merge two sorted arrays - One having big enough buffer to hold another Merge Overlapping Intervals Sort a linked list using merge sort What's the fastest algorithm for sorting a linked list? Merge two arrays efficiently - one sorted, another unsorted Bottom-up Merge Sort Given an integer array of which both first half and second half are sorted. Write a function to merge the two parts to create one single sorted array in place [do not use any extra space]. k-way merge - Merging k sorted arrays of n elements Given two sorted arrays of size m and n respectively (m >> n), how to merge them together? Merge Sort Program to merge two 1-D arrays

Implementing doubly linked list using single pointer Pointer cause decay, references do not. References and Constants Using pointers to break into bytes What is a void pointer? Why can't we perform arithmetic on a void * pointer? Program to check if the stack grows up or down What is a NULL pointer? How is it different from an unitialized pointer? How is a NULL pointer defined? How does free works? Pointer indirection with care What's the difference between const char *p, char * const p and const char * const p? What are the common causes of pointer bugs? C code to dynamically allocate one, two and three dimensional arrays (using malloc()) What is a dangling pointer? What are reference counters with respect to pointers?

Find the maximum distance covered using n bikes Maximum number of chickens you cannot order int atoi( char* pStr ) Reverse a String The Circular Lake Monster Problem Array of 0 and 1, put 0's at even position and 1's at odd position Chain Cut Problem jelly beans Pirates sum it up Palindrome years Red marbles, blue marbles Reverse a string - word by word

K reverse a linked list with increasing K Reverse the doubly linked list Rotate n * n matrix by 90 degrees Rotate n * n matrix by 90 degrees Reverse a c-style string Check If an Integer's Bit Representation Is a Palindrome K – Reverse a linked list Reverse a String using bits How to reverse a stack in place ? Reverse the words in a sentence in place How to reverse a doubly linked list ? Write a C Program to reverse a stack "in place" using recursion ? Reverse a linked list

Implement rand7() using rand5() Monty hall problem - Choose the Correct Door Key Exchange Puzzle Russian Roulette NEWYORK HAIR (Pigeonhole Principle) undefined Brothers and sisters CTRL+A, CTRL+C, CTRL+V CTRL+A, CTRL+C, CTRL+V Match two board configurations of tic-tac-toe problem Given a set of numbers [1-N]. Subsets such that the sum of numbers in the subset is a prime number. Get Sentence from raw text Get Sentence from raw text

Find Nth largest element in the rotated sorted array Find Nth largest element in the rotated sorted array Find the rotation count in rotated sorted array Linear Search on Array Finding an integer that repeats odd number of times in an array of positive integers Find the point of transition from 0 to 1 in an infinite sorted array containings only 0 and 1 . Find the point of transition from 0 to 1 in an infinite sorted array containings only 0 and 1 . Searching the element in sorted infinite array of integers Find the minimum element in the rotated sorted sorted array Find the minimum element in the rotated sorted sorted array Search an element in the sorted rotated array Binary search on Array - Recursive and iterative

For a Given node of a binary tree, print the K distance nodes. Print all nodes that are at distance k from a leaf node Find the distance between 2 nodes in Binary Tree Find the distance between 2 nodes in Binary Tree Given an array arr[], find the maximum j – i such that arr[j] > arr[i] Given an array arr[], find the maximum j – i such that arr[j] > arr[i] Shortest distances between two words in a file Minimum Distance Between Two Elements in an Array Hirschberg’s linear space algorithm in C++ Hirschberg's algorithm Dynamic Programming Algorithm (DPA) for Edit-Distance Dijkstra's Algorithm (Shortest Path)

Max submatrix sum in a matrix Find max subsquare whose border values are all 1 Transform one word into another by changing only one letter at a time Search a long string for small strings in an array Longest word made of other words in an array Find largest 1M numbers in 1B numbers Shortest distances between two words in a file Count the number of 2s between 0 and n Randomly generate m integers from an array of size n Add two numbers without using arithmetic operators Maximum Area Rectangle in Histogram Find the median in a continous stream of numbers

Union and Intersection of two unsorted Linked Lists Create linked lists of all the nodes at each depth for a BST Insertion sort on linked list Selection sort on linked list Sort a linked list using bubble sort Sort a linked list using quick sort Sort a linked list using merge sort What's the fastest algorithm for sorting a linked list? Operation time complexity for a LINKED LIST What is a non-linear datastructure? Link list ADT Stack implementation using linked list

Get Sentence from raw text Get Sentence from raw text Eight Queen Puzzle (likewise N Queen) Print all combinations of n balanced parentheses DFS (Depth First Search) on tree or graph All permutations of a string All permutations of a string Solve the Rat In A Maze problem using backtracking. Representing the Solution Space Balancing Scales Backtracking Algorithms

Transform one word into another by changing only one letter at a time Find if there is a path between two vertices in a directed graph Find if there is a path between two vertices in a directed graph Binary Tree Level-Order Traversal Using Depth First Search (DFS) [Not to USE BFS] BFS (Breadth first search) on Graph Dijkstra's algorithm for equal weight edges using BFS BFS and Undirected Connectivity Dijkstra's Shortest Path Algorithm Graph Search Introduction Graph Traversal Methods BFS (Breadth first search ) OR Level Order Traversal on tree

Convert Binary Tree to Doubly linked list in level order Reverse the doubly linked list Doubly linked list ADT Bubble sort on double linked list Implementing doubly linked list using single pointer Convert Binary Tree to Double Linked List in Zig-Zag Order Double Linked List Structure Vertical Sum of a Binary Tree Vertical Sum of a Binary Tree How to reverse a doubly linked list ? Function to add node to double link list

Convert Binary Tree to Doubly linked list in level order Reverse the doubly linked list Doubly linked list ADT Bubble sort on double linked list Implementing doubly linked list using single pointer Convert Binary Tree to Double Linked List in Zig-Zag Order Double Linked List Structure Vertical Sum of a Binary Tree Vertical Sum of a Binary Tree How to reverse a doubly linked list ? Function to add node to double link list

Minimum Spanning tree MST BFS (Breadth first search) on Graph DFS (Depth first search) for graph Dijkstra's algorithm for equal weight edges using BFS Strongly Connected Graph Topological Sorting BFS and Undirected Connectivity Dijkstra's Shortest Path Algorithm Graph Search Introduction DFS (Depth First Search) on tree or graph BFS (Breadth first search ) OR Level Order Traversal on tree

Deleting the element from the heap Application of heap (in computer science) Building of heap Array Implementation of Heap Array Implementation of Heap Dijkstra's Shortest Path Algorithm Introduction to Heap Heap Sort in java Binary heap : Introduction Heap : Removing the min element using BubbleDown Heap : Inserting an element into a heap using BubbleUp

Get Sentence from raw text Get Sentence from raw text Provide an algorithm such that if an element in an MxN matrix is 0, its entire row and column is set to 0 Determine if a string has all unique characters Remove duplicate characters in a string Replace all spaces in a string with “%20″ in c-style string Check if 2 strings are rotated versions of each other Finding the Start of a Loop in a Linked List Finding the Start of a Loop in a Linked List Anagram Checker–To check if 2 strings are anagrams Anagram Checker–To check if 2 strings are anagrams

Queue ADT Device FIFO queue problem Implement a stack using queue Implement a stack using 2 queues Maximum value in a Sliding Window BFS (Breadth first search) on Graph Priority Queue BFS (Breadth first search ) OR Level Order Traversal on tree Implement a queue in which push_rear(), pop_front() and get_min() are all constant time operations. Implement a Queue using two stacks Circular Queue

Hash Functions find four elements in array whose sum equal to a given number X Pathological Data Sets and Universal Hashing Motivation Hash Tables Bloom filters 2 Sum Problem : Given an integer array and a number T, find all unique pairs of (a, b) whose sum is equal to T 2 Sum Problem : Given an integer array and a number T, find all unique pairs of (a, b) whose sum is equal to T Sorted Linear Hash Table Vertical Sum of a Binary Tree Vertical Sum of a Binary Tree

Allocate a two dimensional array using one call of malloc in C Aligned malloc in C Device FIFO queue problem Prevent reverse engineering of DLLs How to make sure a process doesn’t access unauthorized part of stack What happens after a user presses a key on the keyboard? Direct memory access(DMA) Branch Target buffer Virtual memory, page fault and thrashing To determine whether machine is Little-Endian and Big-Endian?

Find pairs of integers in an array that sum to a value Implement rand7() using rand5() Encode XML Find the frequency of a word in a book Generate english phrase that describes a integer Game of Master Mind Find the maximum (or minimum) of two numbers (or morenumbers) without use of comparison operators or if-else Maximum continuous sum subarray problem Maximum continuous sum subarray problem Swap two number in place without temporary variables.

Common routing protocol Compare and contrast IPv4 and IPv6 What is a network/subnet mask What happens after typing a URL into a browser What is a Graph data structure? Troubleshooting DNS servers Socket Programming In C Simplified IP Addressing Basic Interview Questions on networking Besides communication cost, what is the other source of inefficiency in RPC?

Fizz Buzz Fizz Buzz Sieve of Atkins Algorithm to find out number of factors of a number Program to print all prime factors of a given number To find the list of primes till N Sieve of Eratosthenes Efficient ways to check if number is prime number Prove that number between twin primes is divided by 6 Find the nth Ugly Number

Squeeze all multiple spaces in a string into one space Word Length Frequency Reading from file or Reading integers from file Hirschberg’s linear space algorithm in C++ Sorting binary array - Array containing only 0 and 1 in one pass OR two color sort Sorting binary array - Array containing only 0 and 1 in one pass OR two color sort Bubble sort Quick sort Radix sort Merge Sort

Union and Intersection of two unsorted Linked Lists Remove duplicates from unsorted array Find Local Minimum in an unsorted array with unique elements Find Local Minimum in an unsorted array with unique elements Find the minimum and maximum in the array Find Maximum Value in the unsorted array Find kth largest in an Array find out the largest and second largest number in an array find out the largest and second largest number in an array How to find max. and min. in array using minimum comparisons?

Union and Intersection of two sorted arrays How many time function gets called? Create the REV function from Swap Is there multiply function in 8085 microprocessor Find all the words of Length N which are produced by natural order Set all bits of a number in a range equal to another number Median of 2 sorted arrays of equal size n Median of 2 sorted arrays of equal size n WAP to check whether string is palindrome

Point inside a triangle or NOT Provide an algorithm such that if an element in an MxN matrix is 0, its entire row and column is set to 0 Given a dictionary of word - Group all words into set of anagrams of each other K – Reverse a linked list Globe Walker Spiral printing of a two dimensional array Median of 2 sorted arrays of equal size n Median of 2 sorted arrays of equal size n Important ds question

Finding the next palindrome for the given number Finding the next palindrome for the given number How do I check if a number is a palindrome? How do I check if a number is a palindrome? Check If an Integer's Bit Representation Is a Palindrome Check if singly linked list is Palindrome Find longest palindrome in a string. Find longest palindrome in a string. WAP to check whether string is palindrome

Find the duplicate element most number of times in array of 0 to n-1 Check if array contains duplicates Find duplicates in the ranged array Find the two repeating elements in ranged array Find the two non-repeating elements in a ranged array of repeating elements Find the First Duplicated Integer in an Array containing numbers from 1 to N Without Using Extra Memory Find the First Duplicated Integer in an Array containing numbers from 1 to N Without Using Extra Memory Given numbers from 1 to N+1, with number being from 1 and N and one of the number being repeatative. Find the repeating element. Given an array of n integers from 1 to n with one integer repeated twice

Trie Tutorial Trie Operations Complexity Trie : Searching in Trie Trie : Inserting in Trie Implementing the TRIE ADT in java Trie ADT Scrabble Algorithms Trie examples Tries

Sort an array of strings so that anagrams are next to each other Given a dictionary of word - Group all words into set of anagrams of each other Find anagrams in the array of Strings Anagram Checker–To check if 2 strings are anagrams Anagram Checker–To check if 2 strings are anagrams Anagram Trees : Part 2 Anagram Trees Anagram program implentation

Red Black Tree vs AVL Tree vs B-Tree AVL Tree Index AVL Tree Index AVL Tree : Deleting a node from AVL Tree AVL Tree : Rotations AVL Trees : Inserting a new Item Balanced Search tree AVL tree : Introduction

ER diagram for a database of company ER diagram for a database of company What is denormalization? Design a database with terabytes of data that supports efficient range queries What's Database Normalization ? What's an RDBMS ? Types of Databases What is a Database?

Given an array of 100,000 pixel color values and each of which is an integer in the range (0,255). Give sorting algorithm. Finding an integer that repeats odd number of times in an array of positive integers Sorting Array of Three Kinds or The Dutch National Flag Problem OR three color sort Find the point of transition from 0 to 1 in an infinite sorted array containings only 0 and 1 . Find the point of transition from 0 to 1 in an infinite sorted array containings only 0 and 1 . Counting sort Sorting binary array - Array containing only 0 and 1 in one pass OR two color sort Sorting binary array - Array containing only 0 and 1 in one pass OR two color sort

Deterministic Selection - Select the i th smallest element Find kth largest element from a 2-d sorted array Find kth largest in an Array Find Nth largest element in the rotated sorted array Find Nth largest element in the rotated sorted array Randomized Selection : Selecting the i'th smallest element Find nth largest value in a BST Find nth largest value in a BST

Deterministic Selection - Select the i th smallest element Find kth largest element from a 2-d sorted array Find kth largest in an Array find out the largest and second largest number in an array find out the largest and second largest number in an array Randomized Selection : Selecting the i'th smallest element Find nth largest value in a BST Find nth largest value in a BST

LATIN SQUARE” and its implementation Provide an algorithm such that if an element in an MxN matrix is 0, its entire row and column is set to 0 Rotate n * n matrix by 90 degrees Rotate n * n matrix by 90 degrees Strassen's Subcubic Matrix Multiplication Algorithm Maximum size square sub-matrix with all 1s Spiral printing of a two dimensional array Matrix chain multiplication

Nut and Bolt Problem (OR Key and Lock Problem) - Matching Nuts and Bolts when nuts cannot be compared with nuts and bolts with bolts Sort a linked list using quick sort What's the fastest algorithm for sorting a linked list? Sorting Sorting Array of Three Kinds or The Dutch National Flag Problem OR three color sort Sorting binary array - Array containing only 0 and 1 in one pass OR two color sort Sorting binary array - Array containing only 0 and 1 in one pass OR two color sort Quick sort

Find Nth largest element in the rotated sorted array Find Nth largest element in the rotated sorted array Find the rotation count in rotated sorted array How to rotate an array? Check if 2 strings are rotated versions of each other Find the minimum element in the rotated sorted sorted array Find the minimum element in the rotated sorted sorted array Search an element in the sorted rotated array

Union and Intersection of two sorted arrays Merge two sorted arrays - One having big enough buffer to hold another Merge two arrays efficiently - one sorted, another unsorted k-way merge - Merging k sorted arrays of n elements Median of 2 sorted arrays of equal size n Median of 2 sorted arrays of equal size n Intersection of two sorted lists or 2 sorted arrays Given two sorted arrays of size m and n respectively (m >> n), how to merge them together?

Remove whitespace from a string in-place, in linear time Remove whitespace from a string in-place, in linear time Deleting a node from a singly linked link list Deleting a node in singly linked list if it is less than any of the successor nodes Deleting a node in singly linked list if it is less than any of the successor nodes Duplicate removal in Binary Search Tree Deleting a node from a Binary Search Tree

Direct memory access(DMA) zero sized allocation using malloc Memory Management In C and C + + Program to check if the stack grows up or down What is a NULL pointer? How is it different from an unitialized pointer? How is a NULL pointer defined? What is the difference between malloc() and calloc()? C code to dynamically allocate one, two and three dimensional arrays (using malloc())

Find the longest oscillating subsequence Application of clustering Minimum Spanning tree MST Prim's Algorithm Kruskal's Algorithm An Activity Selection Problem ( Greedy Approach) Dijkstra's Algorithm (Shortest Path)

Maximum continuous sum subarray problem Maximum continuous sum subarray problem Find the First Duplicated Integer in an Array containing numbers from 1 to N Without Using Extra Memory Find the First Duplicated Integer in an Array containing numbers from 1 to N Without Using Extra Memory Find the point of transition from 0 to 1 in an infinite sorted array containings only 0 and 1 . Find the point of transition from 0 to 1 in an infinite sorted array containings only 0 and 1 . Given an array of n integers from 1 to n with one integer repeated twice

How to detect duplicate documents in billions of urls Design a database with terabytes of data that supports efficient range queries How to avoid getting into infinite loops when designing a web crawler Find duplicate elements in the array with 4KB memory only Generate an integer which is not in a file with 4 billion integers, limited memory Sorting 10 GB file of integer with limited ram. Sorting a 2GB file with one string per line

Search a long string for small strings in an array Pattern Searching - Boyer Moore Algorithm – Bad Character Heuristic Searching Patterns - Finite Automata Rabin-Karp Algorithm Suffix Array Suffix tree String Searching Algorithm - Knuth Morris Pratt or KMP Algorithm

Given a number x, less than 100. How will you generate true with probability x/100. How many time function gets called? One shot or at least two shots in three games? Shuffle a deck of cards perfectly The Ant Collision Problem Random number generation Red marbles, blue marbles

Circus tower sorting problem Searching in a sorted array of strings with empty strings Sorting a 2GB file with one string per line Sort an array of strings so that anagrams are next to each other Merge two sorted arrays - One having big enough buffer to hold another Search an element in the sorted rotated array Find an element in matrix in which rows and columns are sorted

Search a long string for small strings in an array Suffix Array Suffix tree Common naming convention : Coding Style BWT (Burrows Wheeler Transform) Encoding Algorithm Hirschberg's algorithm Trie examples

Find increasing 3-tuple (sub-sequence) Longest common substring revisited Reducing the space for LCS lengths Hirschberg’s linear space algorithm in C++ Hirschberg's algorithm Dynamic Programming Algorithm (DPA) for Edit-Distance Longest common subsequence : Dynamic programming

Find first occurrence of a string in another Longest common substring revisited Reducing the space for LCS lengths Hirschberg’s linear space algorithm in C++ Hirschberg's algorithm Dynamic Programming Algorithm (DPA) for Edit-Distance Longest common subsequence : Dynamic programming

Merge two sorted arrays - One having big enough buffer to hold another Merge two arrays efficiently - one sorted, another unsorted Median of 2 sorted arrays of equal size n Median of 2 sorted arrays of equal size n Intersection of two sorted lists or 2 sorted arrays Given two sorted arrays of size m and n respectively (m >> n), how to merge them together? Finding whether 2 arrays are intersecting

Explain ((n & (n-1)) == 0) Provide an algorithm such that if an element in an MxN matrix is 0, its entire row and column is set to 0 Sorting Array of Three Kinds or The Dutch National Flag Problem OR three color sort Find the point of transition from 0 to 1 in an infinite sorted array containings only 0 and 1 . Find the point of transition from 0 to 1 in an infinite sorted array containings only 0 and 1 . Sorting binary array - Array containing only 0 and 1 in one pass OR two color sort Sorting binary array - Array containing only 0 and 1 in one pass OR two color sort

LATIN SQUARE” and its implementation Unique Paths in 2D grid Provide an algorithm such that if an element in an MxN matrix is 0, its entire row and column is set to 0 Find row with maximum number of 1s in sorted matrix Find an element in matrix in which rows and columns are sorted Spiral printing of a two dimensional array

Queue ADT Introduction to Heap What is a Graph data structure? Link list ADT Trie ADT Stack ADT

Queue ADT Introduction to Heap What is a Graph data structure? Link list ADT Trie ADT Stack ADT

Provide an algorithm such that if an element in an MxN matrix is 0, its entire row and column is set to 0 Sorting Array of Three Kinds or The Dutch National Flag Problem OR three color sort Find the point of transition from 0 to 1 in an infinite sorted array containings only 0 and 1 . Find the point of transition from 0 to 1 in an infinite sorted array containings only 0 and 1 . Sorting binary array - Array containing only 0 and 1 in one pass OR two color sort Sorting binary array - Array containing only 0 and 1 in one pass OR two color sort

Point inside a triangle or NOT Point inside a rectangle or not Form a circle from 3 points Find a line which passes the most number of points Find a line to cut two squares in half Determine whether two lines would intersect on a Cartesian plane

Binary Tree Level-Order Traversal Using Depth First Search (DFS) [Not to USE BFS] DFS (Depth first search) for graph Topological Sorting Graph Search Introduction Graph Traversal Methods DFS (Depth First Search) on tree or graph

Fizz Buzz Fizz Buzz Find the kth number with prime factors 3, 5 and 7 Algorithm to find out number of factors of a number Program to print all prime factors of a given number Find the nth Ugly Number

File IO in c++ 1 Reading from file or Reading integers from file File Handling in c Error handling Random access functions File handling in cpp

Given a binary search tree with 2 nodes swapped find number of pairs not following BST properties Given a binary tree with extra field "next pointer" in node, populate the next pointer to the nodes inorder successor Binary Tree In-Order Traversal - Recursive and Iterative Solution Binary tree traversal: Preorder, Inorder, Post-order, BFS, DFS, Level Order, zig zag order Threaded binary tree Inorder successor OR Predecessor of BST node

Stack with find-min/find-max in O(1) time Find the minimum and maximum in the array Find kth largest in an Array find out the largest and second largest number in an array find out the largest and second largest number in an array How to find max. and min. in array using minimum comparisons?

Add two numbers without using arithmetic operators Implement Add,Subtract,Multiplication,Division Using Bit Manipulation Using == operator in better way in cpp sizeof operator Pointer indirection with care Operator Precedence in C & CPP

Fizz Buzz Fizz Buzz Find the kth number with prime factors 3, 5 and 7 Algorithm to find out number of factors of a number Program to print all prime factors of a given number Find the nth Ugly Number

Red Black Tree vs AVL Tree vs B-Tree Red Black Tree Index Red Black Tree – Insertion Red Black Tree – Deletion Red Black tree Balanced Search tree

Red Black Tree vs AVL Tree vs B-Tree Red Black Tree Index Red Black Tree – Insertion Red Black Tree – Deletion Red Black tree Balanced Search tree

Orthogonality Cloud Computing and Virtualization Virtualization Storage virtualization Network virtualization Various Software model

How to test an ATM in a distributed banking system How to test a pen Load test a webpage without using any test tools How to test a canMoveTo(int x, int y) method in a chess game Find the mistake(s) in the code Programming errors cause program crashes in different places every single time

Given two strings str1 and str2, write code to find out if all non-unique elements in str2 are in str1? Determine if a string has all unique characters 2 Sum Problem : Given an integer array and a number T, find all unique pairs of (a, b) whose sum is equal to T 2 Sum Problem : Given an integer array and a number T, find all unique pairs of (a, b) whose sum is equal to T First non repeating element in the array To find the longest substring with unique characters in a given string

Common naming convention : Coding Style Improving coding style into classes Improving coding style into functions or methods Java specific naming convention Specific cases of naming enhancing naming style

CTRL+A, CTRL+C, CTRL+V CTRL+A, CTRL+C, CTRL+V Petrol Bunk in a Circle. Maximum size square sub-matrix with all 1s Longest increasing subsequence

Hash Functions Sorted Linear Hash Table First non repeating element in the array Anagram Checker–To check if 2 strings are anagrams Anagram Checker–To check if 2 strings are anagrams

Insertion sort on linked list What's the fastest algorithm for sorting a linked list? Sorting Insertion sort Comparison sort and Integer sorts

Print a Binary Tree in Zig Zag Level Order or spiral order Given a BST, create a mirror of it. GCD and LCM Merge Sort Euclid's Algorithm : GCD of 2 integers

Removing a loop in a singly linked list Y – shaped Linked List. Algorithm to find the node of intersection of two lists. Finding the Start of a Loop in a Linked List Finding the Start of a Loop in a Linked List Detecting a loop in a linked list

Find a line to cut two squares in half Implement *, -, and / operators using only + Determine whether two lines would intersect on a Cartesian plane One shot or at least two shots in three games? The Ant Collision Problem

Union and Intersection of two unsorted Linked Lists Sort a linked list using merge sort What's the fastest algorithm for sorting a linked list? Bottom-up Merge Sort Sorting

Permutations of every subset of size K All permutations of a string All permutations of a string Scrabble Algorithms Permutations and Combinations of string

Number of Subsets without consecutive elements Combination of all the possible characters in the string All permutations of a string All permutations of a string Permutations and Combinations of string

Given the post order array find if tree is BST Binary Tree Post-Order Traversal - Recursive and Iterative Solution Binary tree traversal: Preorder, Inorder, Post-order, BFS, DFS, Level Order, zig zag order Construct a tree given its inorder and preorder traversal strings. Similarly construct a tree given its inorder and post order traversal strings. Implementing BST in C ( header file )

#ifdef & #endif Using ## and # with define. The preprocessor directives can be redefined anywhere in the program Some macros Using define without assigning value

Find largest sub-matrix with all 1s (not necessarily square) Maximum Area Rectangle in Histogram Program to check if two rectangle overlap or itntersect Program to check if two rectangle overlap or itntersect Given a rectangular (cuboidal for the puritans) cake with a rectangular piece removed (any size or orientation), how would you cut the remainder of the cake into two equal halves with one straight cut of a knife ?

Remove duplicates from unsorted array Remove duplicate characters in a string Remove duplicates from an unsorted linked list Duplicate removal in Binary Search Tree Remove duplicates from the sorted array

Escape all % characters in a string; % is the escape character Implementing strcpy Implementing strcat Implementing strcmp Reverse a String using bits

How to swap two String variables in java without using a third variable Swap odd and even bits in an integer To swap the two nibbles in a byte Swapping 2 variables using macro Swap two number in place without temporary variables.

How to detect duplicate documents in billions of urls Design a database with terabytes of data that supports efficient range queries How to avoid getting into infinite loops when designing a web crawler Find duplicate elements in the array with 4KB memory only Generate an integer which is not in a file with 4 billion integers, limited memory

Atomicity and Atomic operations Can two threads call a synchronized method and normal method at the same time? Scheduling method calls in sequence Thread safe and exception safe singleton design pattern How to measure the time spent in a context switch

Find all the pythagorean triplets in an array of integer 3 sum problem 2 Sum Problem : Given an integer array and a number T, find all unique pairs of (a, b) whose sum is equal to T 2 Sum Problem : Given an integer array and a number T, find all unique pairs of (a, b) whose sum is equal to T

Labour and work problem - 20 women replaced by a men and boy alternatively Ratio and proportion difficult questions Ratio and proportion difficult questions Problems on partnership

Using 5,5,5,5,5 can you make 37 along with any arithmetic operation. Make 3 3 7 7 equal to 24 Make 3 3 7 7 equal to 24 Add arithmetic operators to make 3 1 3 6 = 8 true

Sort a linked list using bubble sort Bubble sort on double linked list What's the fastest algorithm for sorting a linked list? Bubble sort

Types of constructors Use the variable closer to its use How to bound check arrays in cpp / c Using == operator in better way in cpp

Find the longest oscillating subsequence CTS Aptitude Question paper(Yellow) CTS Aptitude Question paper(Yellow) CTS Aptitude Question paper(Yellow)

Find if there is a path between two vertices in a directed graph Find if there is a path between two vertices in a directed graph Strongly Connected Graph BFS and Undirected Connectivity

C++ STL: Iterators and Containers DFS and BFS on trees, with and without recurssion Stack implementation using linked list Stack ADT

Data Type in Data Structure Comparing floats To add two long positive numbers (each represented by linked lists in C) Going beyond range of datatype

Using ## and # with define. The preprocessor directives can be redefined anywhere in the program Some macros Using define without assigning value

Find if there is a path between two vertices in a directed graph Find if there is a path between two vertices in a directed graph What is a Graph data structure? Graph Traversal Methods

Given a series (2,3,4,5,6,8,9,10,12,15,...) where the elements are in multiple of 2,3 and 5. Find the nth element of this sequence Stack of plates Print nodes at k distance from root Find the time period with the maximum number of overlapping intervals

Interval Search Tree Segment trees VS Interval trees VS binary indexed trees VS range trees Program to check if two rectangle overlap or itntersect Program to check if two rectangle overlap or itntersect

Union and Intersection of two sorted arrays Find common nodes from two linked lists using recursion Y – shaped Linked List. Algorithm to find the node of intersection of two lists. Intersection of two sorted lists or 2 sorted arrays

Interval Search Tree Segment trees VS Interval trees VS binary indexed trees VS range trees Merge Overlapping Intervals Find the time period with the maximum number of overlapping intervals

Print a Binary tree in level order with new line after every level Binary Tree Level-Order Traversal Using Depth First Search (DFS) [Not to USE BFS] BFS (Breadth first search ) OR Level Order Traversal on tree Print a Binary Tree in Zig Zag Level Order or spiral order

Integer Multiplication using Karatsuba algorithm Meaning behind Master Method Master Method for Solving Recurrences Basic Mathematics in Algorithms

Median of 2 sorted arrays of equal size n Median of 2 sorted arrays of equal size n Find median of a linked list or a Tree Find the median in a continous stream of numbers

Memory requirement of a program in java The stack and the heap Memory Management Basics Memory Management In C and C + +

Binary tree traversal: Preorder, Inorder, Post-order, BFS, DFS, Level Order, zig zag order Construct a full binary tree from a pre-order list of marked nodes Construct a tree given its inorder and preorder traversal strings. Similarly construct a tree given its inorder and post order traversal strings. Pre Order traversal - Recursive and Iterative solution

Solve the Rat In A Maze problem using backtracking. Write a C program which when compiled and run, prints out a message indicating whether the compiler that it is compiled with, allows /* */ comments to nest. Find the nth Ugly Number Given a string s1 and a string s2, write a snippet to say whether s2 is a rotation of s1 using only one call to strstr routine? (eg given s1 = ABCD and s2 = CDAB, return true, given s1 = ABCD, and s2 = ACBD , return false)

Randomly generate m integers from an array of size n Given a number x, less than 100. How will you generate true with probability x/100. Shuffle a deck of cards perfectly Random number generation

Selection Algorithms Deterministic Selection - Select the i th smallest element Selection sort on linked list Randomized Selection : Selecting the i'th smallest element

Selection sort on linked list What's the fastest algorithm for sorting a linked list? Sorting Selection Sort

Transform one word into another by changing only one letter at a time Bellman ford algorithm - One source shortest path Dijkstra's Shortest Path Algorithm BFS (Breadth first search ) OR Level Order Traversal on tree

Deterministic Selection - Select the i th smallest element Find kth largest in an Array Randomized Selection : Selecting the i'th smallest element Find the smallest window in a string containing all characters of another string

What is a sorting algorithm? Selection Sort What is Bucket Sort? Bubble sort

Boyer Moore Algorithm String Searching Algorithm - Knuth Morris Pratt or KMP Algorithm Karp-Rabin algorithm Pattern matching program using Brute Force Algorithm

Given a set of numbers [1-N]. Subsets such that the sum of numbers in the subset is a prime number. Permutations of every subset of size K Find all subsets of a given set OR Find power set of a given set Find all subsets of a given set OR Find power set of a given set

Find the largest subarray with sum of 0 in the given array find four elements in array whose sum equal to a given number X 2 Sum Problem : Given an integer array and a number T, find all unique pairs of (a, b) whose sum is equal to T 2 Sum Problem : Given an integer array and a number T, find all unique pairs of (a, b) whose sum is equal to T

Sum , factorial Word Length Frequency Taking input as string 1 - " C-String to Int " Calculate pow function

Cloud Computing and Virtualization Virtualization Storage virtualization Network virtualization

Average salary of n people in the room Given a number 123456789, two opearators + and *, value k , find all the such expressions that evaluates to the given value k Median of 2 sorted arrays of equal size n Median of 2 sorted arrays of equal size n

Find the minimum and maximum in the array Find row with maximum number of 1s in sorted matrix Find an element in matrix in which rows and columns are sorted

Asymptotic Notation Growth Rate - The Importance of Asymptotics Algorithm Analysis

Check if Tree is a Balanced Tree IsBST : Check whether the tree provided is BST or not Check whether binary tree are same or not?

Sort an array of strings so that anagrams are next to each other Advantage and disadvantage of datastructures Compare two string literals

Sorting Insertion sort Selection Sort

Skiplists Data Structure to Emulate LRU Cache Concurrent Skip List

Array implementation of stack Array implementation of stack Stack implementation using linked list

Maximize the number of magical gems by passing through array of house Number of steps required to convert string 1 to string2 when only bring character to first index operation is giving Find the least wastage in cutting the Trees?

Print letters followed by their frequency (Run Length Encoding) encodeURIComponent and decodeURIComponent in Java BWT (Burrows Wheeler Transform) Encoding Algorithm

Check if singly linked list is Palindrome Middle of a linked list Detecting a loop in a linked list

Bresenham's circle algorithm Line Drawing Algorithms Routine to draw a circle (x ** 2 + y ** 2 = r ** 2) without making use of any floating point computations at all.

Suggest the selling time and buying time of a share based on stock price prediction Set cover Find a line which passes the most number of points

Given a binary tree with extra field "next pointer" in node, populate the next pointer to the nodes inorder successor Threaded binary tree Inorder successor OR Predecessor of BST node

Algorithm Interview Questions - Set 1 Design Questions - Set 1 Amazon Questions - Set 1

For a Given node of a binary tree, print the K distance nodes. Print all nodes that are at distance k from a leaf node Print nodes at k distance from root

Find the distance between 2 nodes in Binary Tree Find the distance between 2 nodes in Binary Tree First / Lowest common ancestor (LCA) of 2 node in binary tree

Find the distance between 2 nodes in Binary Tree Find the distance between 2 nodes in Binary Tree First / Lowest common ancestor (LCA) of 2 node in binary tree

Lazy Caterer's sequence How to check whether a given number n belongs to fibanocii series? Basic Mathematics in Algorithms

Print a Binary tree in level order with new line after every level Given an array filled with char elements, find the max length of continuous white space Find the longest oscillating subsequence

Find next higher number using exact same digits Next Greater Element in an array Next Greater Element in an array

CTRL+A, CTRL+C, CTRL+V CTRL+A, CTRL+C, CTRL+V Polite Numbers - Calculate all the ways such that a number can be written as sum of 2 or more consecutive numbers

Print all combinations of n balanced parentheses Checking whether the paranthesis are balanced in the expression Stack ADT

Explain ((n & (n-1)) == 0) Count bits set in an integer Code to check if an integer is a power of 2 or not in a single line

Maximum value in a Sliding Window Priority Queue Priority Queue based on Sorted Linked Lists

Taking input as string 1 - " C-String to Int " Self reproducing program in C Hirschberg’s linear space algorithm in C++

Deterministic Selection - Select the i th smallest element Randomized Selection : Selecting the i'th smallest element Quick sort

Some useful resources Pointer cause decay, references do not. References and Constants

Skiplist vs Binary tree Skiplists Skiplist - TOC

Selection Sort What is Bucket Sort? Bubble sort

Find the largest subarray with sum of 0 in the given array Maximum continuous sum subarray problem Maximum continuous sum subarray problem

Algorithm Introduction Hash Tables Balanced Search tree

Maximum value in a Sliding Window Karp-Rabin algorithm Find the smallest window in a string containing all characters of another string

Evaluating postfix expression using stack Checking whether the paranthesis are balanced in the expression

Time and Distance questions Trains

Generate an integer which is not in a file with 4 billion integers, limited memory Determine if a string has all unique characters

Provide an algorithm such that if an element in an MxN matrix is 0, its entire row and column is set to 0 IsBST : Check whether the tree provided is BST or not

Find the k most frequent words from a file Data Structure to Emulate LRU Cache

Finding the celebrity group The Celebrity Problem

Number of ways of representing n cents using quarters, dimes, nickels and pennies Minimum number of coins to get particular amount, given multiple denomination

encodeURIComponent and decodeURIComponent in Java In-Place Character Array Compression

Using pascal keyword Access non const member varible inside a const member function

Constructor in java 1 Types of constructors

Modifying Java Variables (w.r.t c and c++) Java and CPP - the differences and similarities

Secure permutations with block ciphers BWT (Burrows Wheeler Transform) Encoding Algorithm

Give a fast way to multiply a number by 7 Given only putchar (no sprintf, itoa, etc.) write a routine putlong that prints out an unsigned long in decimal

Minimum Cut Problem What is a Graph data structure?

ER diagram for a database of company ER diagram for a database of company

Maximum value in a Sliding Window ArrayDeque + Stack Algorithms

Tree BST - Index

Enums in java Enum in c++

File IO in c++ 1 Reading from file or Reading integers from file

File IO in c++ 1 Reading from file or Reading integers from file

Generic data structures in java C++ STL: Iterators and Containers

Interval Search Tree GitHub: Setup SSH - Permission denied public key error

How does throwing and catching exceptions differ from using setjmp and longjmp? What is the difference between goto and longjmp() and setjmp()?

Next Greater Element in an array Next Greater Element in an array

Vertical Sum of a Binary Tree Vertical Sum of a Binary Tree

K reverse a linked list with increasing K Maximum number of chickens you cannot order

A Needle in the Haystack String Searching Algorithm - Knuth Morris Pratt or KMP Algorithm

Minimum number of coins to get particular amount, given multiple denomination Dynamic-Programming Solution to the 0-1 Knapsack Problem

Skiplist vs Binary tree Skiplists

Find Local Minimum in an unsorted array with unique elements Find Local Minimum in an unsorted array with unique elements

Algorithm to find top 10 search terms in search engine Find the k most frequent words from a file

Strassen's Subcubic Matrix Multiplication Algorithm Matrix chain multiplication

Maximum single sell profit from stock Find increasing 3-tuple (sub-sequence)

Print pascal's triangle Calculate pow function

k-way merge - Merging k sorted arrays of n elements Heap : Inserting an element into a heap using BubbleUp

Minimum Cut Problem What is a Graph data structure?

Maximum single sell profit from stock Find increasing 3-tuple (sub-sequence)

Polite Numbers - Calculate all the ways such that a number can be written as sum of 2 or more consecutive numbers Find next higher number using exact same digits

Stack with find-min/find-max in O(1) time Stack DS to implement constant time Minimum element lookup

Master Method for Solving Recurrences Time complexity - Omega of algorithms

Atomicity and Atomic operations Acronyms used in operating system

Operation time complexity for a LINKED LIST Operation time complexity for an ARRAY

Atomicity and Atomic operations Acronyms used in operating system

2 Sum Problem : Given an integer array and a number T, find all unique pairs of (a, b) whose sum is equal to T 2 Sum Problem : Given an integer array and a number T, find all unique pairs of (a, b) whose sum is equal to T

Get Sentence from raw text Get Sentence from raw text

Binary Tree Post-Order Traversal - Recursive and Iterative Solution Binary tree traversal: Preorder, Inorder, Post-order, BFS, DFS, Level Order, zig zag order

Binary tree traversal: Preorder, Inorder, Post-order, BFS, DFS, Level Order, zig zag order Pre Order traversal - Recursive and Iterative solution

Maximize the number of magical gems by passing through array of house Maximum product sub-array

Unique Paths in 2D grid Solution - #104 Project Euler

Find the time period with the maximum number of overlapping intervals Given an array of 100,000 pixel color values and each of which is an integer in the range (0,255). Give sorting algorithm.

find out the largest and second largest number in an array find out the largest and second largest number in an array

Print all sequences of given length What is special about the following sequence of numbers?

Find the nth Ugly Number Find all sets of consecutive integers that add up to 1000.

Shuffle a deck of cards perfectly Random number generation

Move the Spaces to Front of the String Replace all spaces in a string with “%20″ in c-style string

Using stl sort String Class in cpp(Standard cpp strings)

Maximum single sell profit from stock Suggest the selling time and buying time of a share based on stock price prediction

Meaning behind Master Method Finding time of execution of code in c

Given two strings str1 and str2, write code to find out if all non-unique elements in str2 are in str1? Given two strings A and B, how would you find out if the characters in B were a subset of the characters in A?

BFS (Breadth first search) on Graph What is a Graph data structure?

Union and Intersection of two sorted arrays Merge two arrays efficiently - one sorted, another unsorted

Skiplist vs Binary tree Skiplists

Verbal questions 2 Verbal questions - mixture of words

Implement a function similar to diff command in linux Given the post order array find if tree is BST