题解 | #[NOIP2009]分数线划定#

using namespace std;
int n,m;

struct people{
    int k;
    int s;
}peo[5010];

bool cmp(people &p1 , people &p2){
    if(p1.s == p2.s){
        return p1.k < p2.k;
    }
    return p1.s>p2.s;
}


int main(){

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

        }
        sort(peo+1,peo+1+n,cmp);
        int index = floor(m*1.5);
        int score = peo[index].s;
        while (peo[index].s == peo[index+1].s){
            index++;
        }
        
        printf("%d %d\n",score,index);
        for(int i =1 ; i<=index ;++i){
            printf("%d %d\n",peo[i].k,peo[i].s);

        }


    }

}