谁能告诉我为什么20分？

#include<bits/stdc++.h>
using namespace std;
int n,m,f,l,ans;
struct node{
	int id,ans;
}q[5005];
bool cmp(node x,node y){
	return x.ans>y.ans;
}
int main(){
	scanf("%d%d",&n,&m);
	for(int i=1;i<=n;i++)scanf("%d%d",&q[i].id,&q[i].ans);
	sort(q+1,q+1+n,cmp);
	f=floor(m*1.5);
	f=q[f].ans;
	printf("%d ",f);
	for(int i=1;i<=n;i++){
		if(q[i].ans>=f){
			if(q[i-1].ans<f)l=i;
			ans++;
		}
	}
	printf("%d\n",ans);
	for(int i=l;i<=l+ans-1;i++){
		if(q[i].ans==q[i+1].ans){
			if(q[i].id>q[i+1].id)swap(q[i],q[i+1]);
		}
		printf("%d %d\n",q[i].id,q[i].ans);
	}
	return 0;
}