POJ-2028

#include<iostream>#include<map>#include<utility>using namespace std;int main(int argc, char *argv[]){int n,q;while(cin>>n>>q,n!=0 || q!=0){map<int,int> date;map<int,int>::iterator pos=date.begin();for(int i=0;i<n;i++){int m;cin>>m;for(int j=0;j<m;j++){int mj;cin>>mj;pos=date.find(mj);if(pos==date.end()){date.insert(pair<int,int>(mj,1));}else{pos->second++;}}}int cd=-1;for(map<int,int>::iterator iter=date.begin();iter!=date.end();++iter){if(iter->second>cd){pos=iter;cd=iter->second;}}int result;if(pos->second>=q){result=pos->first;}else{result=0;}cout<<result<<endl;}return 0;}