这题没有做过类似的，所以感觉还是有点难度的，先来看下题目： A sequence of numbers is called a wiggle sequence if the differences b...

Given a set of distinct positive integers, find the largest subset such that every pair (Si, Sj) of ...

The thief has found himself a new place for his thievery again. There is only one entrance to this a...

Given n, how many structurally unique BST’s (binary search trees) that store values 1 …...

Given an integer n, generate all structurally unique BST’s (binary search trees) that store va...

这题挺有意思，主要是要找出是否有3个元素递增，这3个元素的索引必须依次增加但是不要求临近。首先贴题目： Given an unsorted array return whether an increa...

这题的follow up实在太难，没想出来，就贴一个简单的做法。首先先贴一下题目： Given an unsorted array nums , reorder it such that nums[0...

这题我做的时候用了动态规划，但是也只是能满足时间复杂度小于O(N2)，先看下题目 Given an unsorted array of integers, find the length of lon...

You are playing the following Bulls and Cows game with your friend: You write down a number and ask ...

又是一道single number题目，这类题目一般都是依赖位操作，先给出题目： Given an array of numbers nums , in which exactly two eleme...