Find Minimum in Rotated Sorted Array leetcode

原题链接

直接贴代码，这道题是

search in rotated sorted array leetcode

的前面部分！

class Solution {
public:
    int findMin(vector<int>& nums) {
        if (nums.empty())
            return -1;
        int res = find(nums, 0, nums.size()-1);//好神奇，第二个参数无论减或者不减1，都不影响该题的结果
        if (res == -1)
            return -1;
        return nums[res];
    }
    int find(vector<int>& nums, int l, int r)
    {
        if (l>r || l >= nums.size())
            return -1;
        int mid = (l + r) / 2;
        if (nums[l] <= nums[mid])
        {
            int pos = find(nums, mid + 1, r);
            if (pos == -1)
                return l;
            return nums[l]<nums[pos] ? l : pos;
        }
        else
        {
            int pos = find(nums, l, mid - 1);
            if (pos == -1)
                return mid;
            return nums[mid]<nums[pos] ? mid : pos;
        }
    }
};