Submission #563681

#	Time	Username	Problem	Language	Result	Execution time	Memory
563681		colossal_pepe	Paths (BOI18_paths)	C++17	100 / 100	533 ms	616520 KiB

paths

#include <iostream>
#include <vector>
#include <cstring>
using namespace std;
 
using ll = long long;
 
int n, m, k, c[300005];
vector<vector<int>> g;
 
ll solve() {
    ll ans = 0;
    if (k < 2) return ans;
    ll dp_1[n][k];
    memset(dp_1, 0, sizeof(dp_1));
    for (int u = 0; u < n; u++) {
        for (int v : g[u]) {
            dp_1[u][c[v]] += 1;
        }
        for (int c1 = 0; c1 < k; c1++) {
            if (c1 == c[u]) continue;
            ans += dp_1[u][c1];
        }
    }
    if (k < 3) return ans;
    ll dp_2[n][k][k];
    memset(dp_2, 0, sizeof(dp_2));
    for (int u = 0; u < n; u++) {
        for (int v : g[u]) {
            for (int c1 = 0; c1 < k; c1++) {
                dp_2[u][c[v]][c1] += dp_1[v][c1];
            }
        }
        for (int c1 = 0; c1 < k; c1++) {
            if (c1 == c[u]) continue;
            for (int c2 = 0; c2 < k; c2++) {
                if (c2 == c[u] or c2 == c1) continue;
                ans += dp_2[u][c1][c2];
            }
        }
    }
    if (k < 4) return ans;
    ll dp_3[n][k][k][k];
    memset(dp_3, 0, sizeof(dp_3));
    for (int u = 0; u < n; u++) {
        for (int v : g[u]) {
            for (int c1 = 0; c1 < k; c1++) {
                for (int c2 = 0; c2 < k; c2++) {
                    dp_3[u][c[v]][c1][c2] += dp_2[v][c1][c2];
                }
            }
        }
        for (int c1 = 0; c1 < k; c1++) {
            if (c1 == c[u]) continue;
            for (int c2 = 0; c2 < k; c2++) {
                if (c2 == c[u] or c2 == c1) continue;
                for (int c3 = 0; c3 < k; c3++) {
                    if (c3 == c[u] or c3 == c1 or c3 == c2) continue;
                    ans += dp_3[u][c1][c2][c3];
                }
            }
        }
    }
    if (k < 5) return ans;
    ll dp_4[n][k][k][k][k];
    memset(dp_4, 0, sizeof(dp_4));
    for (int u = 0; u < n; u++) {
        for (int v : g[u]) {
            for (int c1 = 0; c1 < k; c1++) {
                for (int c2 = 0; c2 < k; c2++) {
                    for (int c3 = 0; c3 < k; c3++) {
                        dp_4[u][c[v]][c1][c2][c3] += dp_3[v][c1][c2][c3];
                    }
                }
            }
        }
        for (int c1 = 0; c1 < k; c1++) {
            if (c1 == c[u]) continue;
            for (int c2 = 0; c2 < k; c2++) {
                if (c2 == c[u] or c2 == c1) continue;
                for (int c3 = 0; c3 < k; c3++) {
                    if (c3 == c[u] or c3 == c2 or c3 == c1) continue;
                    for (int c4 = 0; c4 < k; c4++) {
                        if (c4 == c[u] or c4 == c3 or c4 == c2 or c4 == c1) continue;
                        ans += dp_4[u][c1][c2][c3][c4];
                    }
                }
            }
        }
    }
    return ans;
}
 
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cin >> n >> m >> k;
    g.resize(n);
    for (int i = 0; i < n; i++) {
        cin >> c[i];
        c[i]--;
    }
    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