Given a collection of distinct numbers, return all possible permutations.

Given a collection of numbers that might contain duplicates, return all possible unique permutations.

Implement next permutation, which rearranges numbers into the lexicographically next greater permutation of numbers.

Given an array of integers, return indices of the two numbers such that they add up to a specific target.

You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order and each of their nodes contain a single...

There are N integers (1<=N<=65537) A1, A2,.. AN (0<=Ai<=10^9). You need to find amount of such pairs (i, j) that 1<=i<j<=N and A[i]>A[j].

Vasya learned definition of median of three numbers. He says, “Median of three numbers is the number located in the middle when numbers are ordered in non-desce...

Write a program that outputs the string representation of numbers from 1 to n.

如果你到现在搞不懂这两个符号的区别，这问题就跟学英语记不住周一到周日的正确拼写一样严重，那么就非常有必要花3分钟跟着这篇文章复习一遍。

https://leetcode-cn.com/problems/bitwise-and-of-numbers-range/