在一个从左到右，从上到下均有序的二维数组中，找到从小到第k个数字，这里需要注意，不要求一定要是唯一的值，即假设存在这样一个序列1,2,2,3，则第三个数字是2而不是3。

Suppose an array sorted in ascending order is rotated at some pivot unknown to you beforehand.(i.e., [0,1,2,4,5,6,7] might become [4,5,6,7,0,1,2]).Find the minimum element.You may assume no duplica…

Given an integer array nums, find the contiguous subarray within an array (containing at least one number) which has the largest product.

A peak element is an element that is greater than its neighbors.Given an input array nums, where nums[i] ≠ nums[i+1], find a peak element and return its index.The array may contain multiple peaks, …

Implement an iterator over a binary search tree (BST). Your iterator will be initialized with the root node of a BST.Calling next() will return the next smallest number in the BST.

一个猜数字游戏，数字区间为1~n，每猜一次，会有人告诉你猜中了或者当前的数字是大于结果值还是小于结果值。猜对则本次猜测免费，猜错则本次猜测需要花费和数字等额的金钱。问如果要确保能够猜中数字，最少要花费…

Given a binary tree, return the inorder traversal of its nodes’ values.

Given a binary tree, imagine yourself standing on the right side of it, return the values of the nodes you can see ordered from top to bottom.

Given a list of non negative integers, arrange them such that they form the largest number.

Compare two version numbers version1 and version2.If version1 > version2 return 1; if version1 < version2 return -1;otherwise return 0.You may assume that the version strings are non-empty an…