Find the Celebrity Suppose you are at a party with n people (labeled from 0 to n - 1) and among them, there may exist one celebrity. The definition ...

letter at a random position. Find the letter that was a ...

to find an index mapping P, from A to B. A mapping P[ ...

Given a binary tree, return all duplicate subtrees. For each kind of duplicate subtrees, you o ...

Given an array of integers nums, write a method that returns the "pivot" index of this array. We ...

Given an array nums containing n + 1 integers where each integer is between 1 and n (inclusive), ...

Given an integer n, find the closest integer (not including itself), which is a palindrome. The 'closest' is defined as absolute difference ...

Given an array A of strings made only from lowercase letters, return a list of all characters that ...