Find Minimum in Rotated Sorted Array

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.

所有的旋轉數組，都可以用這種方法來解決：

class Solution {
public:
    int findMin(vector<int>& nums) {
        int start = 0, end = nums.size()-1;
        while(start<end) {
            int mid = start + (end-start)/2;
            if(nums[mid]<nums[end]) 
                end = mid;
            else if(nums[mid]>nums[end])
                start = mid+1;
            else
                end--; //之所以要從end開始，是為了防止有序數比如：1 2 3，這種類型的case出現
        }
        return nums[start];
    }
};