Submission #678568

#	Time	Username	Problem	Language	Result	Execution time	Memory
678568		hollwo_pelw	Commuter Pass (JOI18_commuter_pass)	C++17	100 / 100	343 ms	21020 KiB

commuter_pass

#include <bits/stdc++.h>
// #include <ext/pb_ds/assoc_container.hpp>
// #include <ext/pb_ds/trie_policy.hpp>
// #include <ext/rope>

using namespace std;
// using namespace __gnu_cxx;
// using namespace __gnu_pbds;

void Hollwo_Pelw();

signed main(){
#ifndef hollwo_pelw_local
	if (fopen(".inp", "r"))
		assert(freopen(".inp", "r", stdin)), assert(freopen(".out", "w", stdout));
#else
	using namespace chrono;
	auto start = steady_clock::now();
#endif
	cin.tie(0), cout.tie(0) -> sync_with_stdio(0);
	int testcases = 1;
	// cin >> testcases;
	for (int test = 1; test <= testcases; test++){
		// cout << "Case #" << test << ": ";
		Hollwo_Pelw();
	}
#ifdef hollwo_pelw_local
	auto end = steady_clock::now();
	cout << "\nExecution time : " << duration_cast<milliseconds> (end - start).count() << "[ms]" << endl;
#endif
}

#define int long long

const int N = 1e5 + 5;

int n, m, S, T, U, V;
vector<pair<int, int>> adj[N];

int ds[N], dt[N], du[N], dv[N], fu[N], fv[N];

void dijkstra(int s, int *d) {
	fill(d + 1, d + n + 1, 1e18);
	priority_queue<pair<int, int>> pq;

	pq.emplace(d[s] = 0, s);

	while (!pq.empty()) {
		auto [D, u] = pq.top(); pq.pop(), D = -D;
		if (d[u] != D) continue;

		for (auto [v, w] : adj[u]) {
			if (d[v] > D + w)
				pq.emplace(- (d[v] = D + w), v);
		}
	}
}

void Hollwo_Pelw(){
	cin >> n >> m >> S >> T >> U >> V;
	for (int u, v, w; m --; ) {
		cin >> u >> v >> w;
		adj[u].emplace_back(v, w);
		adj[v].emplace_back(u, w);
	}
	dijkstra(S, ds);
	dijkstra(T, dt);
	dijkstra(U, du);
	dijkstra(V, dv);

	vector<pair<int, int>> ord;

	for (int i = 1; i <= n; i++) {
		if (ds[i] + dt[i] == ds[T]) {
			// in path
			ord.emplace_back(dt[i], i);
		}
	}

	sort(ord.begin(), ord.end());

	fill(fu + 1, fu + n + 1, 1e18);
	fill(fv + 1, fv + n + 1, 1e18);

	int res = du[V];

	for (auto [_, x] : ord) {
		fu[x] = du[x], fv[x] = dv[x];
		for (auto [y, w] : adj[x]) {
			if (dt[y] + w == dt[x]) {
				fu[x] = min(fu[x], fu[y]);
				fv[x] = min(fv[x], fv[y]);
			}
		}
		res = min({res, fu[x] + dv[x], fv[x] + du[x]});
	}

	cout << res << '\n';
}

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