Coderbyte

Study
Find the middle element of a linked list

Method to find the middle element of a linked list in linear time.
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.
Print the power set of a given set

Solution for printing all possible subsets of a given set.
Subset sum problem

Important computer science question where the goal is to find a subset that sums to some number.
Determine if a tree is a subtree of a larger binary tree

Use tree traversal algorithms to solve this tree algorithm question.
Generate all balanced bracket combinations

Interesting question that asks you to print all combinations of pairs of brackets.
Find all string combinations of only 0, 1 and ?

Print all possible strings of 0's and 1's where the ? is a wildcard.
Insert an interval into a list of sorted disjoint intervals

Solution for inserting an interval into an already sorted list of disjoint intervals.
Implement a queue using two stacks

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

Recursion is an important topic to understand when learning a language, so this tutorial provides a simple example.
Stock maximum profit

Solution that explains how to calculate the maxiumum profit that could be made in a list of stock prices.
Quickly calculate the cube root of a number

Algorithm to calculate the cube root of a given number in constant time.

Challenges
Array Addition

For this challenge you will determine if numbers in an array can add up to a certain number in the array.

3988 solutions

Solution
Binary Search Tree LCA

For this challenge you will attempt to find the lowest common ancestor of a binary search tree.

185 solutions

Solution
Bracket Combinations

This challenge will require knowledge of basic mathematical combinations.

97 solutions

Solution
Counting Anagrams

For this challenge you will determine how many anagrams exist in a string.

125 solutions

Solution
Max Subarray

For this challenge you will determine the largest sum subarray.

499 solutions

Solution
K Unique Characters

For this challenge you will be searching a string for a particular substring.

330 solutions

Solution
Bitmap Holes

For this challenge you will be searching within a 2D matrix.

240 solutions

Solution
Maximal Rectangle

For this challenge you will be searching a matrix for the largest rectangle submatrix.

29 solutions

Solution
Symmetric Tree

For this challenge you will traverse a binary tree and determine if it is symmetric.

208 solutions

Solution
Binary Tree LCA

For this challenge you will attempt to find the lowest common ancestor of a binary tree.

104 solutions

Solution
LRU Cache

For this challenge you will determine the order of elements within a simulated cache.

120 solutions

Solution
Wave Sorting

For this challenge you will determine if numbers in an array can be sorted in a particular way.

860 solutions

Solution
Tree Constructor

For this challenge you will determine if an array of integer pairs can form a binary tree properly.

112 solutions

Solution
Longest Increasing Sequence

For this challenge you will compute the length of the longest increasing subsequence.

814 solutions

Solution
Two Sum

For this challenge you will determine if two elements can sum to some larger number.

1237 solutions

Solution
Power Set Count

For this challenge you will determine the length of a power set.

784 solutions

Solution
Word Split

For this challenge you will attempt to split a long string of characters into actual words.

256 solutions

Solution
City Traffic

For this challenge you will be finding the maximum traffic that will enter a node.

24 solutions

Solution