Cracking the Coding Interview

Here are my answers to the questions from Cracking the Coding Interview, Fourth Edition.

Data Structures

Arrays and Strings

Question 1.1

Implement an algorithm to determine if a string has all unique characters. What if you can not use additional data structures?

Solution: JavaScript

Question 1.2

Write code to reverse a C-Style String. (C-String means that "abcd" is represented as five characters, including the null character.)

Solution: JavaScript

Question 1.3

Design an algorithm and write code to remove the duplicate characters in a string without using any additional buffer. NOTE: One or two additional variables are fine. An extra copy of the array is not. FOLLOW UP: Write the test cases for this method.

Solution: JavaScript

Question 1.4

Write a method to decide if two strings are anagrams or not.

Solution: JavaScript

Question 1.5

Write a method to replace all spaces in a string with '%20'.

Solution: JavaScript

Question 1.6

Given an image represented by an NxN matrix, where each pixel in the image is 4 bytes, write a method to rotate the image by 90 degrees. Can you do this in place?

Solution: JavaScript