154. Find Minimum in Rotated Sorted Array II(循环数组查找)

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.

The array may contain duplicates.

Example 1:

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

Example 2:

Input: [2,2,2,0,1]
Output: 0

 

class Solution {
public:
    int findMin(vector<int>& nums) {
        int len=nums.size();
        if(len==1) return nums[0];
        int low=0,high=len-1;  //有重复的数字从mid 和high 比较来辨别 寻找的位于左半部分还是右半部分，没有的话用 mid和low位置比较划分
        while(low<=high){
            int mid=low+(high-low)/2;
            if(nums[mid]<nums[high]) {
                high=mid;
            }else if(nums[mid]>nums[high]){
                low=mid+1;
            }else{
            high--;
            }
        }
        return nums[low];
    }
};