Determine if a number is a perfect number.

Find the ranks of all participants.

Find the Base 7 representation of a number.

Find the mode in a Binary Search Tree.

Find whether all characters of words are in one row on a keyboard.

Find how long Ashe is poisoned.

Find the smallest integer greater than a prefix sum.

Construct the most balanced rectangle.

Find the smallest number whose product of its digits are divisible by another integer.

Find the maximum number of consecutive ones in an array.

Return the formatted license plate number.

Find the complement of an integer.

Find the perimeter of the island.

Determine the hamming distance between two integers.

Find the missing elements in an array.

Can you feed all the children?

Find the number of rows we can fill with coins.

Find the number of segments in a string.

Add two strings together.

Find the third largest number in an array.