解法1: #include<bits/stdc++.h> using namespace std; int n,m,i,f,k[5001],s[5001],sub[5001]; bool cmp(int a,int b){ if(s[a] == s[b]){ return k[a]<k[b]; } return s[a] > s[b]; } int main(){ cin>>n>>m; for(int i = 1;i<=n;++i){ cin>>k[sub[i]=i]>>s[i]; } sort(sub+1,sub+n+1,cmp); f = s[sub[int(m*1.5)]];//分数线 for(i=1;s[sub[i]]>=f;++i); cout<<f<<" "<<i-1<<endl; for(i=1;s[sub[i]]>=f;++i){ cout<<k[sub[i]]<<" "<<s[sub[i]]<<endl; } }