Two sum problem

A popular interview question that requires you to determine if two numbers in an array sum to a specific value. A solution can be written that runs in linear time.

Find all duplicates in an array (version 1)

Solution for finding all duplicates in an array where the elements range from 1 to n-1.

Find all duplicates in an array (version 2)

A common interview question where your goal is to find all duplicates in an array in linear time.

Print the power set of a given set

Solution for printing all possible subsets of a given set.

Dutch national flag sorting problem

Question and solution for sorting an array of 0's, 1's, and 2's in place and in linear time.

Implement a queue using two stacks

Solution for how to implement a queue using the stack data structure.

Arrays and Lists

Improve your algorithms knowledge with this course on sorting, linked lists, hash tables, queues, and more.