看起来很难，实际上很水

#include <bits/stdc++.h>
using namespace std;

struct Node{
    int k; // id
    int s; // 成绩
}a[100010];

int n, m;

bool cmp(Node x, Node y){
    if (x.s!=y.s) return x.s>y.s;
    return x.k<y.k;
}

int main(){
    cin >> n >> m;
    for (int i=1;i<=n;i++){
        cin >> a[i].k >> a[i].s;
    }

    sort(a+1, a+n+1, cmp);

    int temp = m*1.5;
    int ans1=0;
    int ans2 = 0;

    while (a[temp+1].s==a[temp].s && temp<=n) temp++;
        
    ans2 = temp;
    ans1 = a[ans2].s;
    cout << ans1 << " " << ans2 << "\n";

    for (int i=1;i<=ans2;i++){
        cout << a[i].k << " " << a[i].s << "\n";
    }
    
    return 0;
}