Find the length of the Longest Palindrome.

Convert a number to its Hexadecimal representation.

Find the sum of all the left leaves of a Binary Tree.

Find the minimum number of presses to type a word on a telephone keypad.

Determine if one string is a subsequence of another.

Find the extra character between two strings.

Find the first unique character in a string.

Determine if we can generate a Ransom Note from a magazine.

Guess the correct number.

Find whether a number is a perfect square.

Find the intersection of two arrays, Part II.

Determine the intersection of two arrays.

Reverse the vowels of a string.

Reverse a String.

Determine if a number is a power of 4.

Count the number of bits in a set of integers.

Determine whether a number is a power of three.

Play the Nim Game.

Find whether a word follows a pattern.

Move the zeroes in the array to the end.