今天心情不好，就做一道

class Solution {
public:
    int countTarget(vector<int>& scores, int target) {
        return help(scores,target)-help(scores,target-1);
    }
    int help(vector<int>&scores,int target)
    {
        int left = 0;
        int right = scores.size()-1;
        while(left <= right)
        {
            int mid = (left+right)/2;
            if(scores[mid] <= target) left=mid+1;
            else right = mid-1;
        }
        return left;
    }
};