Given a non-negative integer num, repeatedly add all its digits until th...

Implement atoi to convert a string to an integer.Hint: Carefully conside...

Reverse digits of an integer.Example1: x = 123, return 321Example2: x = ...

The string "PAYPALISHIRING" is written in a zigzag pattern on a given nu...

Given a string s, find the longest palindromic substring in s. You may a...

There are two sorted arrays nums1 and nums2 of size m and n respectively...

Given a string, find the length of the longest substring without repeati...

You are given two non-empty linked lists representing two non-negative i...

Given an array of integers, return indices of the two numbers such that ...