Submission #887676

#	Time	Username	Problem	Language	Result	Execution time	Memory
887676		votranngocvy	Paths (BOI18_paths)	C++14	100 / 100	257 ms	103096 KiB

paths

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

#define int long long
const int N = 3e5 + 5;
int n,m,k,a[N];
vector<int>g[N];

namespace sub1 {
    int ans = 0;
    bool vis[10];
    void dfs(int u) {
        vis[a[u]] = true;
        for (auto v: g[u]) {
            if (vis[a[v]]) continue;
            ans++;
            dfs(v);
        }
        vis[a[u]] = false;
    }
    void solve() {
        for (int i = 1; i <= n; i++) dfs(i);
        cout << ans << "\n";
    }
}

namespace sol {
    int dp[N][35];
    void solve() {
        for (int i = 1; i <= n; i++) dp[i][(1 << a[i])] = 1;
        for (int mask = 0; mask < (1 << k); mask++) {
            for (int u = 1; u <= n; u++) {
                if (dp[u][mask] == 0) continue;
                for (auto v: g[u]) {
                    if (mask & (1 << a[v])) continue;
                    dp[v][mask | (1 << a[v])] += dp[u][mask];
                }
            }
        }
        int ans = 0;
        for (int i = 1; i <= n; i++)
            for (int mask = 0; mask < (1 << k); mask++)
                if (__builtin_popcount(mask) >= 2) ans += dp[i][mask];
        cout << ans << "\n";
    }
}

signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    cin >> n >> m >> k;
    for (int i = 1; i <= n; i++) {
        cin >> a[i];
        a[i]--;
    }
    for (int i = 1; i <= m; i++) {
        int u,v;
        cin >> u >> v;
        g[u].push_back(v);
        g[v].push_back(u);
    }
    sol::solve();
}

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