Submission #1249019

#	Time	Username	Problem	Language	Result	Execution time	Memory
1249019		khoile08	Commuter Pass (JOI18_commuter_pass)	C++20	15 / 100	2094 ms	22336 KiB

commuter_pass

#include <bits/stdc++.h>
using namespace std;
#define FOR(i, a, b) for(int i = a; i <= b; i++)
#define FOD(i, a, b) for(int i = a; i >= b; i--)
#define int long long
#define fi first
#define se second
#define ll long long
#define db double
#define ii pair<int,int>
#define pb push_back
#define MASK(i) (1LL << i)
#define sq(i) (1LL * (i) * (i))
#define task "khoile08"

const ll INF = 1e18;
const int inf = 1e9;
const int N = 1e5 + 5;

int n, m, S, T, U, V, ans;
vector<ii> g[N];
ll d[4][N], dp[N];

void Dijkstra(int sr, int t) {
	priority_queue<ii,vector<ii>,greater<ii>> pq;
	pq.push({0, sr});
	FOR(i, 1, n) d[t][i] = INF;
	d[t][sr] = 0;
	while(!pq.empty()) {
		ll cost = pq.top().fi;
		int u = pq.top().se;
		pq.pop();
		if(cost != d[t][u]) continue;
		for(ii H : g[u]) {
			int v = H.fi;
			int w = H.se;
			if(d[t][v] > d[t][u] + w) {
				d[t][v] = d[t][u] + w;
				pq.push({d[t][v], v});
			}
		}
	}
}

void Dfs(int u, int t) {
	dp[u] = d[0][u];
	for(auto H : g[u]) {
		int v = H.fi;
		int w = H.se;
		if(d[t][u] == d[t][v] + w) { // on sp
			Dfs(v, t);
			dp[u] = min(dp[u], dp[v]);
		}
	}
	ans = min(ans, dp[u] + d[1][u]);
}

void Solve() {
	Dijkstra(U, 0);
	Dijkstra(V, 1);
	Dijkstra(S, 2);
	Dijkstra(T, 3);

	ans = INF;
	FOR(i, 1, n) dp[i] = INF;
	Dfs(T, 2);
	FOR(i, 1, n) dp[i] = INF;
	Dfs(S, 3);
	cout << min(d[0][V], ans) << '\n';
}

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

	int tc = 1;
	// cin >> tc;
	while(tc--) {
		cin >> n >> m >> S >> T >> U >> V;
		FOR(i, 1, m) {
			int u, v, w;
			cin >> u >> v >> w;
			g[u].pb({v, w});
			g[v].pb({u, w});
		}
		Solve();
	}
}

• Subtask 1: 0 / 16
• Subtask 2: 15 / 15
• Subtask 3: 0 / 24
• Subtask 4: 0 / 45