PAT-A-1134

bad Code

#include <iostream>
#include <vector>

using namespace std;
int v, e, k, qu,q;
const int maxn = 10005;
vector<int> edge[maxn];
vector<int> cop[maxn];

int main() {
    scanf("%d%d", &v, &e);
    for (int i = 0; i < e; i++) {
        int v1, v2;
        scanf("%d%d", &v1, &v2);
        edge[v1].push_back(v2);
        edge[v2].push_back(v1);
    }
    scanf("%d", &k);
    while (k--) {
        for (int i = 0; i < maxn; i++) {
            cop[i] = edge[i];
        }
        scanf("%d", &qu);
        while(qu--){
            scanf("%d", &q);
            //每个顶点i来说，iq，qi 不为-1则变-1
            for (int i = 0; i < maxn; i++) {
                for (int j = 0; j < cop[i].size(); j++) {
                    //i->q
                    if (cop[i][j] == q) {
                        cop[i][j] = -1;
                    }
                }
                for (int j = 0; j < cop[q].size(); j++) {
                    //q->i
                    if (cop[q][j] == i) cop[q][j] = -1;
                }
            }
        }
        bool flag = true;
        for (int i = 0; i < maxn; i++) {
            for (auto it :cop[i]) {
                if (it != -1) flag = false;
            }
        }
        if (flag) printf("Yes\n");
        else printf("No\n");
    }
    return 0;
}