Leetcode: 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.

这种类型的题总是不能信手拈来，要举例半天，为什么呢。。。技巧在哪里？

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