Leetcode Find Minimum in Rotated Sorted Array

Problem

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.

Solution

一开始看题目以为是确定这个数组在某一个点旋转了，跑了一下才发现也有可能没有旋转，完全是一个正常的数组，汗。。。。

每次拿最右边的值和中间值比较，保证去旋转点可能在的那一半就好。

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