NC16625 分数线划定

有一个坑点，卡到了80%的样例。坑点在注释中标明了

#include <iostream>
#include <algorithm>
using namespace std;
const int maxn = 5010;
struct Node {
    int id;
    int score;
}node[maxn];
bool cmp(Node a, Node b) {
    if (a.score == b.score)return a.id < b.id;
    return a.score > b.score;
}
int main()
{
    int n, m;
    cin >> n >> m;
    for (int i = 0; i < n; i++) {
        cin >> node[i].id >> node[i].score;
    }
    sort(node, node + n, cmp);
    int score=node[int(m*1.5)-1].score;//注意这里要-1，因为是从下标0开始的
    int ans=0;
    for(int i=0;i<n;i++){
        if(node[i].score>=score)ans++;
    }
    cout<<score<<" "<<ans<<endl;
    for(int i=0;i<ans;i++){
        cout<<node[i].id<<" "<<node[i].score<<endl;
    }
}