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.

public class Solution {
    public int findMin(int[] num) {
        if (num.length==0) {
            return 0;
        }
        int minnum=num[0];
        for (int i : num) {
            if (i<minnum) {
                minnum=i;
                break;
            }
        }
        return minnum;
    }
}