Submission #404201

#	Time	Username	Problem	Language	Result	Execution time	Memory
404201		rama_pang	Paths (BOI18_paths)	C++17	100 / 100	571 ms	70708 KiB

paths

#include <bits/stdc++.h>
using namespace std;

int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);

  int N, M, K;
  cin >> N >> M >> K;
  vector<int> A(N);
  for (int i = 0; i < N; i++) {
    cin >> A[i];
    A[i]--;
  }
  vector<vector<int>> adj(N);
  while (M--) {
    int u, v;
    cin >> u >> v;
    u--, v--;
    adj[u].emplace_back(v);
    adj[v].emplace_back(u);
  }

  vector<vector<long long>> dp(N, vector<long long>(1 << K));
  for (int mask = (1 << K) - 1; mask >= 0; mask--) {
    for (int i = 0; i < N; i++) if ((mask >> A[i]) & 1) {
      dp[i][mask] += 1;
    }
    for (int i = 0; i < N; i++) if ((mask >> A[i]) & 1) {
      for (auto j : adj[i]) if (((mask >> A[j]) & 1) ^ 1) {
        dp[i][mask] += dp[j][mask | (1 << A[j])];
      }
    }
  }

  long long ans = 0;
  for (int i = 0; i < N; i++) {
    ans += dp[i][1 << A[i]];
  }

  cout << ans - N << '\n';
  return 0;
}

• Subtask 1: 23 / 23
• Subtask 2: 20 / 20
• Subtask 3: 27 / 27
• Subtask 4: 30 / 30