Submission #104789

#	Time	Username	Problem	Language	Result	Execution time	Memory
104789		daili	Paths (BOI18_paths)	C++14	100 / 100	800 ms	74220 KiB

paths

#include <bits/stdc++.h>

using namespace std;

#define int long long
long long solve(vector<vector<int>> &adj, int current, int colsUsed, int K, vector<int> &colors, vector<vector<long long>> &dp)
{
    int cnt = 1;

    if (dp[current][colsUsed])
    {
      return dp[current][colsUsed];
    }

    for (auto u : adj[current])
    {
        if ((colsUsed & (1 << colors[u])) == 0)
        {
            cnt += solve(adj, u, colsUsed ^ (1 << colors[u]), K, colors, dp);
        }
    }
    dp[current][colsUsed] = cnt;
    return cnt;
}

signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    int n, m, K;
    cin >> n >> m >> K;

    vector<int> cols;
    for (int i = 0; i < n; i++)
    {
        int x;
        cin >> x;
        x--;

        cols.push_back(x);
    }

    vector<vector<int>> graph(n);
    for (int i = 0; i < m; i++)
    {
      int a, b;
      cin >> a >> b;

      a--; b--;
      graph[a].push_back(b);
      graph[b].push_back(a);
    }

    vector<vector<long long>> dp(n+1, vector<long long> (1 << K));

    int res = 0;
    for (int i = 0; i < n; i++)
    {
      res += solve(graph, i, (1 << cols[i]), K, cols, dp);
    }
    cout << res - n;


    return 0;
}

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