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.

#if 0  //O(nlogn)
class Solution {
public:
    int findMin(std::vector<int> &num) {
        std::sort(num.begin(),num.end());
		return num[0];
    }
};
#endif
#if 1  //O(logn)
class Solution {
public:
    int findMin(std::vector<int> &num) {
		int left = 0, right = num.size() - 1;
		while (left <= right)
		{
			int mid = left + (right - left) / 2;
			if(num[left] <= num[mid] && num[mid] <= num[right])
			{
				break;
			}
			if(num[mid] < num[left])
			{
				right = mid;
			}
			else if(num[mid] > num[right])
			{
				left = mid + 1;
			}
		}
		return num[left];
    }
};
#endif // 1