Variables and Data Types Introduction

 Posted on July 18, 2014  (Last modified on August 7, 2020)  |  2 minutes  |  Kinshuk Chandra

In computer science and computer programming, a data type or simply type is a classification identifying one of various types of data, such as Real, Integer or Boolean, that determines the possible values for that type; the operations that can be done on values of that type; the meaning of the data; and the way values of that type can be stored. Variables: Variables are placeholders used to store values; they have names and data types. [Read More]
kodeknight 

Encode XML

 Posted on July 18, 2014  (Last modified on August 7, 2020)  |  2 minutes  |  Kinshuk Chandra

Problem Since XML is very verbose, you are given a way of encoding it where each tag gets mapped to a pre-defined integer value The language/grammar is as follows: Element –> Element Attr* END Element END [aka, encode the element tag, then its attributes, then tack on an END character, then encode its children, then another end tag] Attr –> Tag Value [assume all values are strings] END –> 01 [Read More]
kodeknight  Moderate  CrackingTheCodingInterview 

Find the frequency of a word in a book

 Posted on July 18, 2014  (Last modified on August 7, 2020)  |  1 minutes  |  Kinshuk Chandra

Problem Design a method to find the frequency of occurrences of any given word in a book. Solution Just scan the word, trim it and put in hashtable. Now, when searching lower case it and search it. Hashtable<String, Integer> setupDictionary(String book) { Hashtable<String, Integer> table = new Hashtable<String, Integer>(); for (String word : book) { word = word.toLowerCase(); if (word.trim() != "") { if (!table.containsKey(word)) table.put(word, 0); table.put(word, table. [Read More]
kodeknight  Moderate  CrackingTheCodingInterview 

Generate english phrase that describes a integer

 Posted on July 18, 2014  (Last modified on August 7, 2020)  |  3 minutes  |  Kinshuk Chandra

Problem Given an integer between 0 and 999,999, print an English phrase that describes the integer (e.g., “One Thousand, Two Hundred and Thirty Four”). Solution private static final Map<Integer, String> digitsToStrings; static { Map<Integer, String> aMap = new HashMap<Integer, String>(); aMap.put(1, "One"); aMap.put(2, "Two"); aMap.put(3, "Three"); aMap.put(4, "Four"); aMap.put(5, "Five"); aMap.put(6, "Six"); aMap.put(7, "Seven"); aMap.put(8, "Eight"); aMap.put(9, "Nine"); aMap.put(10, "Ten"); aMap.put(11, "Eleven"); aMap.put(12, "Twelve"); aMap.put(13, "Thirteen"); aMap.put(14, "Fourteen"); aMap. [Read More]
kodeknight  Moderate  CrackingTheCodingInterview 

Game of Master Mind

 Posted on July 18, 2014  (Last modified on August 7, 2020)  |  2 minutes  |  Kinshuk Chandra

Problem The Game of Master Mind is played as follows: The computer has four slots containing balls that are red (R), yellow (Y), green (G) or blue (B). For example, the computer might have RGGB (e.g., Slot #1 is red, Slots #2 and #3 are green, Slot #4 is blue). You, the user, are trying to guess the solution You might, for example, guess YRGB. When you guess the correct color for the correct slot, you get a “hit” If you guess a color that exists but is in the wrong slot, you get a “pseudo-hit”. [Read More]
kodeknight  Moderate  incomplete  CrackingTheCodingInterview 

Find the maximum (or minimum) of two numbers (or morenumbers) without use of comparison operators or if-else

 Posted on July 18, 2014  (Last modified on August 7, 2020)  |  3 minutes  |  Kinshuk Chandra

Problem Write a method which finds the maximum of two numbers You should not use if-else or any other comparison operator EXAMPLE Input: 5, 10 Output: 10 Solution Method 1 - Using arithematic operator Let a is greater than b, and M is the mid point, then: then max = (a + b) / 2 + |a - b| / 2 Method 2 - Using most significant bit [Read More]
kodeknight  Moderate  CrackingTheCodingInterview  bits 

Number of trailing zeros in a factorial

 Posted on July 18, 2014  (Last modified on August 7, 2020)  |  1 minutes  |  Kinshuk Chandra

Problem Write an algorithm which computes the number of trailing zeros in n factorial. Solution The trailing zeros are constructed by multiplying pairs of 2 and 5. So to count the number of trailing zeros, we need to count the number of pairs of 2 and 5. For a factorial, there are way more number of factor 2 than 5 so we just need to count the number of factor 5 in the factorial. [Read More]
kodeknight  CrackingTheCodingInterview 

Check if someone has won tic-tac-toe

 Posted on July 18, 2014  (Last modified on August 7, 2020)  |  2 minutes  |  Kinshuk Chandra

Problem Design an algorithm to figure out if someone has won in a game of tic-tac-toe. Solution I’ve written a game of tic-tac-toe in Java, and my current method of determining the end of the game accounts for the following possible scenarios for the game being over: The board is full, and no winner has yet been declared: Game is a draw. Cross has won. Circle has won. [Read More]
kodeknight  incomplete  CrackingTheCodingInterview 

Road Race

 Posted on June 13, 2014  (Last modified on August 7, 2020)  |  1 minutes  |  Kinshuk Chandra

Problem

In the final stretch of a road race, you pass the 2nd-place runner right before crossing the finish line. What place do you finish in?Pu

Solution

Second place. You would have had to pass the first place racer to have finished in first place.

kodeknight  brainteaser 

Sum of Hats

 Posted on June 12, 2014  (Last modified on August 7, 2020)  |  1 minutes  |  Kinshuk Chandra

Problem There are 3 people Abel,Bill and Clark.Three of them have numbers written on their hats.One can only see the numbers written on others hats and can not see the number written on his own hat. Sum of numbers on any two 2 hats is equal to the number on the third hat.Now the following event occurs 1. Abel was asked about the number on his hat.He replied “Don’t Know” [Read More]
kodeknight  brainteaser  incomplete