class Solution {

public:

    vector<int> searchRange(vector<int>& nums, int target) {

        vector<int> res(,-);

        int left=;int right=nums.size()-;

        if(right<) return res;

        if(right==){

            if(nums[]==target) return{,};

            else return res;

        }

        int mid;

        //寻找lower_bound

        while(left<right){

            int mid=left+(right-left)/;

            if(nums[mid]<target)

                left=mid+;

            else

                right=mid;

        }

        if(nums[left]==target){

            res[]=left;

            int step=;

            while(step+left<nums.size()&&nums[step+left]==target)

                step++;

            res[]=left+step-;

        }

        return res;

    }

};