STL(map)

#include<iostream>
#include<string>
#include<map>
using namespace std;
int main(){
  map<string,int>dict;
  dict["Jone"]=1;
  dict["Tom"]=2;
  dict["Mary"]=1;
  if(dict.count("Mary")){
    count<<"Mary is in class"<<dict["Mary"];
    dict["Mary"]=5;
  }
  for(map<string,int>:: iterator it=dict.begin();it!=dict.end();it++){
    cout>>it->first<<"is in class"it->second<<endl;
  }
  dict.clear();
  return 0;
}

#include<iostream>
#include<map>
#include<string>
using namespace std;
int main(){
    map<int,mao<string,int> >info;
    int n;
    cin >>n;
    for(int i=0;i<n;i++){
      int class_id;
      string name;
      cin>>class_id>>name;
      info[class_id][name]++;
    }
    for(map<int,map<string,int> >::iterator it=info.begin();it1!=info.end();it1++){
    for(map<string,int>::iterator it2=it1->second.begin();it2!=it1->second.end();it2++){
      cout<<"There are"<<it2->second<<"people named" it2->first<<"in class"<<it1->first<<endl
    }
    }
}