借助 assert 发现 Subtask3 第一个点并不满足 $m \leq 24$ 的限制

#include <cstdio>
#include <iostream>
#include <algorithm>
#include <vector>
#include <cstring>
#include <assert.h>

using std::cin;
using std::cout;
using ll = long long;

const int N = 1e5;
const ll MOD = 1e9 + 7;

int n, m;
struct Edge {int u, v;} Ed[N + 5];

int q;
struct Qry {int k;} Q[N + 5];

int main() {
  cin >> n >> m >> q;
  assert (m <= 24);

  for (int i = 1; i <= m; ++i) cin >> Ed[i].u >> Ed[i].v;
  for (int i = 1; i <= q; ++i) cin >> Q[i].k;
  return 0;
}