Given the head of a linked list head, in which each node contains an integer value. Between every pair of adjacent nodes, insert a new node with a value equal to the greatest common divisor of them. R

Alice has n balloons arranged on a rope. You are given a 0-indexed string colors where colors[i] is the color of the ith balloon. Alice wants the rope to be colorful. She does not want two consecutive

You are given two 0-indexed integer arrays player1 and player2, that represent the number of pins that player 1 and player 2 hit in a bowling game, respectively. The bowling game consists of n turns,

Given a string path, where path[i] = ‘N’, ‘S’, ‘E’ or ‘W’, each representing moving one unit north, south, east, or west, respectively. You start at the origin (0, 0) on a 2D plane and walk on th

Given the root of a perfect binary tree, reverse the node values at each odd level of the tree. For example, suppose the node values at level 3 are [2,1,3,4,7,11,29,18], then it should become [18,29,1

You are given a 0-indexed m x n binary matrix grid. A 0-indexed m x n difference matrix diff is created with the following procedure:Let the number of ones in the ith row be onesRowi.Let the number of

You are given a string s consisting of lowercase English letters, and you are allowed to perform operations on it. In one operation, you can replace a character in s with another lowercase English let

You are given a string num, representing a large integer. Return the largest-valued odd integer (as a string) that is a non-empty substring of num, or an empty string “” if no odd integer exists. A su

Hercy wants to save money for his first car. He puts money in the Leetcode bank every day. He starts by putting in $1 on Monday, the first day. Every day from Tuesday to Sunday, he will put in $1 more

You are given an integer n, the number of teams in a tournament that has strange rules:If the current number of teams is even, each team gets paired with another team. A total of n / 2 matches ar