1047 Student List for Course (25 分)

#include<bits/stdc++.h>
using namespace std;
#define ll long long
const int maxn=40010;

vector<int>v[maxn];
char mp[maxn][10];
bool cmp(int a,int b)
{
    return strcmp(mp[a],mp[b])<0;
}
int main()
{
    int n,k;
    scanf("%d%d",&n,&k);
    for(int i=0;i<n;i++)
    {
        char s[100];
        scanf("%s",mp[i]);

        int num;
        scanf("%d",&num);
        for(int j=0;j<num;j++)
        {
            int x;
            scanf("%d",&x);

            v[x].push_back(i);

        }
    }
    for(int i=1;i<=k;i++)
    {
        printf("%d %d\n",i,v[i].size());
        sort(v[i].begin(),v[i].end(),cmp);
        for(int j=0;j<v[i].size();j++)
        {
            printf("%s\n",mp[v[i][j]]);
        }
    }
    return 0;
}