Submission #564743

#	Time	Username	Problem	Language	Result	Execution time	Memory
564743		colossal_pepe	Paths (BOI18_paths)	C++17	100 / 100	659 ms	70800 KiB

paths

#include <iostream>
#include <vector>
using namespace std;

using ll = long long;

int n, m, k;
vector<int> c;
vector<vector<int>> g;

ll solve() {
    vector<vector<ll>> dp(n, vector<ll>((1 << k), 0));
    for (int u = 0; u < n; u++) {
        dp[u][(1 << c[u])] = 1;
    }
    ll ans = 0;
    for (int i = 2; i <= k; i++) {
        for (int u = 0; u < n; u++) {
            for (int v : g[u]) {
                if (c[u] == c[v]) continue;
                for (int mask = 0; mask < (1 << k); mask++) {
                    if (__builtin_popcount(mask) == i and mask&(1 << c[u]) and mask&(1 << c[v])) {
                        ans += dp[v][mask - (1 << c[u])];
                        dp[u][mask] += dp[v][mask - (1 << c[u])];
                    }
                }
            }
        }
    }
    return ans;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cin >> n >> m >> k;
    c.resize(n), g.resize(n);
    for (int u = 0; u < n; u++) {
        cin >> c[u];
        c[u]--;
    }
    while (m--) {
        int u, v;
        cin >> u >> v;
        u--, v--;
        g[u].push_back(v);
        g[v].push_back(u);
    }
    cout << solve() << endl;
    return 0;
}

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