153. 寻找旋转排序数组中的最小值

class Solution {
    public int findMin(int[] nums) {
        if(nums==null||nums.length==0){
            return -1;
        }
        int start=0;
        int end=nums.length-1;
        while(start<=end){
            int mid=start+(end-start)/2;
            if(nums[start]<=nums[end]){
                return nums[start];
            }
            if(nums[mid]<=nums[end]){
                end=mid;
            }else{
                start=mid+1;
            }
        }
        return -1;
    }
}