Submission #510027

#	Time	Username	Problem	Language	Result	Execution time	Memory
510027		haxorman	Paths (BOI18_paths)	C++14	100 / 100	476 ms	208456 KiB

paths

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

#define int long long

const int mxN = 3e5 + 7;
const int mxK = 39;

int n, m, k, color[mxN], dp[mxN][mxK][2];
vector<int> graph[mxN];

int dfs(int u, int mask, bool sz) {
	if (dp[u][mask][sz]) {
		return dp[u][mask][sz];
	}

	if (sz) {
		dp[u][mask][sz] = 1;
	}

	for (auto v : graph[u]) {
		if (!(mask & (1 << color[v]))) {
			dp[u][mask][sz] += dfs(v, mask | (1 << color[v]), 1);
		}
	}

	return dp[u][mask][sz];
}

int32_t main() {
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

	cin >> n >> m >> k;

	for (int u = 1; u <= n; ++u) {
		cin >> color[u];
		color[u]--;
	}
	
	for (int i = 0; i < m; ++i) {
		int u, v;
		cin >> u >> v;

		graph[u].push_back(v);
		graph[v].push_back(u);
	}
	
	int ans = 0;
	for (int i = 1; i <= n; ++i) {
		ans += dfs(i, 1 << color[i], 0);
	}
	cout << ans << "\n";
}

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