L2-025 分而治之

血亏 一道基础题目 多输出了东西导致只拿了7分
https://pintia.cn/problem-sets/994805046380707840/problems/994805056195379200

#include <stdio.h>
#include <iostream>
#include <cstring>
#include <vector>
#include <queue>
#include <map>
#include <set>
#include <sstream>
#include <algorithm>
using namespace std;
int N, M;
//const int MAXN = , MAXM = 0;
//typedef long long ll;
const int si = 10007;
vector <int> G[si];
int gongxia[si];

int flag = 0;
void solve() {
    int cnt = 0;
    for (int i = 1; i <= N; i++) {
        flag = 0;
        if (gongxia[i]) continue;
        for (int j = 0; j < G[i].size(); j++) {
            int to = G[i][j];
            if (!gongxia[to]) {
                flag = 1;
                return;
            }
        }
    }
}

int main() {
    int a, b, k;
    scanf("%d %d", &N, &M);
    for (int i = 0; i < M; i++) {
        scanf("%d %d", &a, &b);
        G[a].push_back(b);
        G[b].push_back(a);
    }
    for (int i = 1; i <= N; i++) {
        if (G[i].size() == 0) {
            gongxia[i] = 1;
        //  cout << i;
        }
    }
    cin >> k;
    for (int i = 0, b; i < k; i++) {
        fill(gongxia, gongxia + si, 0);
        cin >> b;
        for (int j = 0, tep; j < b; j++) {
            scanf("%d", &tep);
            gongxia[tep] = 1;
        }
        solve();
        if (flag) printf("NO\n");
        else printf("YES\n");
    }

    return 0;
}