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 duplicate exists in the array.

Example 1:

Input: [3,4,5,1,2] Output: 1

Example 2:

Input: [4,5,6,7,0,1,2]Output: 0

难度：medium

题目：假设一个按升序排序的数组在某个未知的轴上旋转。假定数组中没有重复元素。

思路：分情况二叉搜索

Runtime: 0 ms, faster than 100.00% of Java online submissions for Find Minimum in Rotated Sorted Array.

Memory Usage: 37.6 MB, less than 100.00% of Java online submissions for Find Minimum in Rotated Sorted Array.

class Solution {    public int findMin(int[] nums) {        return findMin(nums, 0, nums.length - 1);    }        public int findMin(int[] nums, int left, int right) {        int mid = left + (right - left) / 2;        // 升序        if (nums[left] <= nums[mid] && nums[mid] <= nums[right]) {            return nums[left];        }        // 降序        if (nums[left] >= nums[mid] && nums[mid] >= nums[right]) {            return nums[right];        }        // 升序占大降序占小        if (nums[left] >= nums[mid]) {            return findMin(nums, left, mid);        }         // 升序占小降序占大        return findMin(nums, mid, right);    }}