Suppose a sorted array is rotated at some pivot unknown to you beforehand.

(i.e.,0 1 2 4 5 6 7might become4 5 6 7 0 1 2).

Find the minimum element.

Notice

You may assume no duplicate exists in the array.

Have you met this question in a real interview?

Yes

Example

Given[4, 5, 6, 7, 0, 1, 2]return0

Answer: https://leetcode.com/problems/find-minimum-in-rotated-sorted-array/description/

Tips: for rotate sorted array -- find the first position which is the number less than the last number in array

如果条件设定这个数组里可能有重复的数，则不能用二分法只能暴力循环比对!

https://leetcode.com/problems/search-in-rotated-sorted-array/description/

public class Solution {
    public int FindMin(int[] nums) {

        if (nums == null || nums.Length == 0){
            return -1;
        }

        int start = 0, end = nums.Length -1;

        int lastNumber = nums[end];
        while (start +1 < end){
            int mid = start + (end -start)/2;
                if (nums[mid]< lastNumber){
                    end = mid;
                }else{
                    start = mid;
                }
        }
        if (nums[start] < nums[end]){
            return nums[start];
        }
        return nums[end];
    }
}

}