[LintCode] 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.

Example

Given [4, 5, 6, 7, 0, 1, 2] return 0

Note

You may assume no duplicate exists in the array.

Note: mid could fall on the minimum point.

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