Submission #83533

#	Time	Username	Problem	Language	Result	Execution time	Memory
83533		Noam527	Paths (BOI18_paths)	C++17	100 / 100	656 ms	135916 KiB

paths

#include <bits/stdc++.h>
#include <unordered_map>
#include <unordered_set>
#define endl '\n'
#define fast ios::sync_with_stdio(0), cin.tie(0)
#define debug cout << "ok" << endl
#define finish(x) return cout << x << endl, 0
typedef long long ll;
typedef long double ldb;
const int md = 1e9 + 7, inf = 1e9 + 7;
const ll hs = 199;
const ldb eps = 1e-9, pi = acos(-1);
using namespace std;

int n, m, k;
vector<int> c;
vector<vector<int>> g;
vector<ll> dp[32];

ll calc(int v, int mask) {
	if ((mask & (1 << c[v])) == 0) return 0;
	if (dp[mask][v] != -1) return dp[mask][v];
	if (mask == (1 << c[v])) return dp[mask][v] = 1;
	dp[mask][v] = 0;
	for (const auto &i : g[v]) {
		dp[mask][v] += calc(i, mask ^ (1 << c[v]));
	}
	return dp[mask][v];
}

int main() {
	fast;
	cin >> n >> m >> k;
	c.resize(n);
	for (auto &i : c) cin >> i, --i;
	g.resize(n);
	for (int i = 0, u, v; i < m; i++) {
		cin >> u >> v;
		--u, --v;
		g[u].push_back(v);
		g[v].push_back(u);
	}
	for (int i = 0; i < (1 << k); i++) dp[i].resize(n, -1);
	ll ans = 0;
	for (int i = 0; i < n; i++) for (int mask = 0; mask < (1 << k); mask++)
		if (mask != (mask & -mask))
			ans += calc(i, mask);
	finish(ans);
}

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