[LeetCode]Find Minimum in Rotated Sorted Array

Find Minimum in Rotated Sorted Array

Suppose a sorted array 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.

 

O(n)时间复杂度的算法很容易实现，二分搜索可以将时间复杂度降为O(logn)。

要搞清楚各个参数测设置以及判定条件的设置。

class Solution {
public:
    int findMin(vector<int>& nums) {
        if(nums.size()==0) return 0;
        int left=0,right=nums.size()-1;
        while(left<right && nums[left]>=nums[right])
        {
            int mid = (left+right)/2;
            if(nums[mid]>nums[right])
            {
                left = mid+1;
            }
            else
            {
                right = mid;
            }
        }
        return nums[left];
    }
};