【Lintcode】159.Find Minimum in Rotated Sorted Array

题目：

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.

题解：

 

class Solution {
public:
    /**
     * @param nums: a rotated sorted array
     * @return: the minimum number in the array
     */
    int findMin(vector<int> &nums) {
        int start = 0, end = nums.size() - 1;
        while (start + 1 < end) {
            int mid = start + (end - start) / 2;
            if (nums[mid] > nums[end]) {
                start = mid;
            } else {
                end = mid;
            }
        }
        
        if (nums[start] < nums[end]) {
            return nums[start];
        } else {
            return nums[end];
        }
    }
};