Submission #851929

#	Time	Username	Problem	Language	Result	Execution time	Memory
851929		stdfloat	Commuter Pass (JOI18_commuter_pass)	C++17	100 / 100	262 ms	15548 KiB

commuter_pass

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

using ll = long long;

int main() {
	ios::sync_with_stdio(false); cin.tie(nullptr);

	int n, m, s, t, u, v;
	cin >> n >> m >> s >> t >> u >> v;

	vector<pair<int, int>> E[n + 1];
	while (m--) {
		int a, b, c;
		cin >> a >> b >> c;
		E[a].push_back({b, c});
		E[b].push_back({a, c});
	}

	auto f = [&](int st) -> vector<ll>{
		vector<ll> dis(n + 1, LLONG_MAX); dis[st] = 0;
		priority_queue<pair<ll, int>, vector<pair<ll, int>>, greater<>> q; q.push({0, st});
		while (!q.empty()) {
			int x = q.top().second; q.pop();
			for (auto i : E[x]) {
				if (dis[x] + i.second < dis[i.first]) {
					dis[i.first] = dis[x] + i.second;
					q.push({dis[i.first], i.first});
				}
			}
		}
		return dis;
	};

	vector<ll> diss = f(s), dist = f(t), disu = f(u), disv = f(v);

	vector<bool> vis(n + 1);
	priority_queue<vector<ll>> q;
	q.push({0, -disu[s] - disv[s], s, disu[s], disv[s]});
	while (!q.empty()) {
		vector<ll> u = q.top(); q.pop();
		if (u[2] == t) {
			return cout << min(disu[v], -u[1]), 0;
		}
		if (vis[u[2]]) continue;
		vis[u[2]] = true;
		for (auto i : E[u[2]]) {
			if (diss[u[2]] + i.second == diss[i.first] && diss[i.first] + dist[i.first] == diss[t]) {
				ll a = min(u[3], disu[i.first]), b = min(u[4], disv[i.first]);
				q.push({-diss[i.first], - a - b, i.first, a, b});
			}
		}
	}
}

• Subtask 1: 16 / 16
• Subtask 2: 15 / 15
• Subtask 3: 24 / 24
• Subtask 4: 45 / 45