PAT 1047 Student List for Course (25 分)

#include <iostream>
#include <string.h>
#include <algorithm>
#include <vector>
using namespace std;
int main() {
    int n,k,c,temp;
    cin>>n>>k;
    vector<vector<string>> course(k+1);
    string name;
    for(int i=0;i<n;++i){
        cin>>name>>c;
        for(int j=0;j<c;++j){
            cin>>temp;
            course[temp].push_back(name);
        }
    }
    for(int i=1;i<=k;++i){
        int size=course[i].size();
        cout<<i<<" "<<size<<endl;
        sort(course[i].begin(),course[i].end());
        for(int j=0;j<size;++j)
            cout<<course[i][j]<<endl;
    }
    return 0;
}