1039 Course List for Student

#include"iostream"
#include"unordered_map"
#include"set"
using namespace std;

int main() {
    int n,k;
    scanf("%d%d",&n,&k);
    unordered_map<string,set<int> > ans;
    for(int i = 0; i < k; ++i) {
        int course_index,stuNum;
        scanf("%d%d",&course_index,&stuNum);
        for(int j = 0; j < stuNum; ++j) {
            string name;
            cin>>name;
            ans[name].insert(course_index);
        }
    }
    for(int i = 0; i < n; ++i) {
        string name;
        cin>>name;
        cout<<name<<" "<<ans[name].size();
        for(auto it = ans[name].begin(); it != ans[name].end(); ++it) {
            printf(" %d",*it);
        }
        printf("\n");
    }
}