oj.uz

Submission #575431

# Submission time Handle Problem Language Result Execution time Memory
575431 2022-06-10T12:14:04 Z _karan_gandhi Commuter Pass (JOI18_commuter_pass) C++17
100 / 100
 269 ms 25732 KB 
#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define all(v) v.begin(), v.end()
#define endl '\n'
#define pl(var) " [" << #var << ": " << (var) << "] "

template<typename A, typename B> ostream& operator<<(ostream &cout, pair<A, B> const &p) { return cout << "[" << p.first << ", " << p.second << "]"; }
template<typename A> ostream& operator<<(ostream &cout, vector<A> const &v) { cout << "["; for(ll int i = 0; i < (ll int)v.size(); i++) {if (i) cout << ", "; cout << v[i];} return cout << "]";}

ll int inf = 1e18;

vector<ll int> distancesS, distancesU, distancesV, distances;
vector<vector<pair<int, ll int>>> adj;
vector<vector<int>> from;
vector<bool> vis;

void djkstra(ll int start) {
	fill(all(distances), inf);

	distances[start] = 0;
	priority_queue<pair<ll int, ll int>> pq;
	pq.emplace(0, start);

	while (pq.size()) {
		ll int node, d;
		tie(d, node) = pq.top();
		pq.pop();
		d = -1 * d;

		if (distances[node] != d) continue;

		for (auto [v, wt] : adj[node]) {
			ll int new_dist = d + wt;

			if (new_dist < distances[v]) {
				distances[v] = new_dist;
				pq.emplace(-new_dist, v);
			}
		}
	}
}

ll int ans = 0;
vector<ll int> mem;

ll int dfs2(ll int u) {
	if (vis[u]) return mem[u];
	vis[u] = 1;

	ll int mn = inf;
	for (ll int v : from[u]) {
		mn = min(mn, dfs2(v));
	}

	ans = min(ans, mn + distancesV[u]);
	return mem[u] = min(mn, distancesU[u]);
}

void solve() {
	int n, m; cin >> n >> m;
	int s, t; cin >> s >> t; s--, t--;
	int U, V; cin >> U >> V; U--, V--;

	adj.resize(n);
	vis.resize(n);
	distances.resize(n);
	distancesS.resize(n);
	distancesU.resize(n);
	distancesV.resize(n);
	from.resize(n);
	mem.resize(n);
	

	for (ll int i = 0; i < m; i++) {
		ll int a, b, c; cin >> a >> b >> c;
		a--, b--;
		adj[a].emplace_back(b, c);
		adj[b].emplace_back(a, c);
	}

	// run djkstra
	djkstra(U); for (ll int i = 0; i < n; i++) distancesU[i] = distances[i];
	djkstra(V); for (ll int i = 0; i < n; i++) distancesV[i] = distances[i];

	auto djkstra1 = [&]() {
		// I know u and v
		fill(all(distancesS), inf);

		distancesS[s] = 0;

		priority_queue<pair<ll int, ll int>> pq;
		pq.emplace(0, s);

		while (pq.size()) {
			auto [dist, node] = pq.top();
			pq.pop();
			dist = dist * -1;

			if (distancesS[node] != dist) continue;

			for (auto [v, wt] : adj[node]) {
				ll int new_dist = dist + wt;

				if (new_dist < distancesS[v]) {
					distancesS[v] = new_dist;
					from[v].clear();
					from[v].push_back(node);
					pq.emplace(-new_dist, v);
				} else if (new_dist == distancesS[v]) {
					from[v].push_back(node);
				}
			}
		}
	};

	djkstra1();

	ans = distancesU[V];
	fill(all(mem), 0);
	dfs2(t);
	fill(all(vis), 0);
	distancesV.swap(distancesU);
	fill(all(mem), inf);
	dfs2(t);

	cout << ans << endl;
}

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

	ll int T = 1;
	// cin >> T;
	while (T--) 
		solve();

	return 0;
}

Subtask #1
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 241 ms 23500 KB Output is correct
2 Correct 269 ms 22684 KB Output is correct
3 Correct 252 ms 25496 KB Output is correct
4 Correct 233 ms 22600 KB Output is correct
5 Correct 239 ms 22468 KB Output is correct
6 Correct 240 ms 23288 KB Output is correct
7 Correct 250 ms 22760 KB Output is correct
8 Correct 247 ms 22840 KB Output is correct
9 Correct 232 ms 22488 KB Output is correct
10 Correct 207 ms 22320 KB Output is correct
11 Correct 100 ms 18936 KB Output is correct
12 Correct 250 ms 22676 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 248 ms 23984 KB Output is correct
2 Correct 249 ms 24008 KB Output is correct
3 Correct 247 ms 23724 KB Output is correct
4 Correct 252 ms 24020 KB Output is correct
5 Correct 258 ms 24252 KB Output is correct
6 Correct 255 ms 25172 KB Output is correct
7 Correct 263 ms 25732 KB Output is correct
8 Correct 262 ms 24064 KB Output is correct
9 Correct 258 ms 24428 KB Output is correct
10 Correct 249 ms 23776 KB Output is correct
11 Correct 114 ms 19916 KB Output is correct
12 Correct 250 ms 25288 KB Output is correct

Subtask #3
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 1748 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 13 ms 3028 KB Output is correct
5 Correct 6 ms 1620 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 1 ms 468 KB Output is correct
8 Correct 2 ms 468 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 6 ms 1620 KB Output is correct
11 Correct 0 ms 340 KB Output is correct
12 Correct 1 ms 340 KB Output is correct
13 Correct 1 ms 340 KB Output is correct
14 Correct 1 ms 340 KB Output is correct
15 Correct 1 ms 340 KB Output is correct

Subtask #4
45.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 241 ms 23500 KB Output is correct
2 Correct 269 ms 22684 KB Output is correct
3 Correct 252 ms 25496 KB Output is correct
4 Correct 233 ms 22600 KB Output is correct
5 Correct 239 ms 22468 KB Output is correct
6 Correct 240 ms 23288 KB Output is correct
7 Correct 250 ms 22760 KB Output is correct
8 Correct 247 ms 22840 KB Output is correct
9 Correct 232 ms 22488 KB Output is correct
10 Correct 207 ms 22320 KB Output is correct
11 Correct 100 ms 18936 KB Output is correct
12 Correct 250 ms 22676 KB Output is correct
13 Correct 248 ms 23984 KB Output is correct
14 Correct 249 ms 24008 KB Output is correct
15 Correct 247 ms 23724 KB Output is correct
16 Correct 252 ms 24020 KB Output is correct
17 Correct 258 ms 24252 KB Output is correct
18 Correct 255 ms 25172 KB Output is correct
19 Correct 263 ms 25732 KB Output is correct
20 Correct 262 ms 24064 KB Output is correct
21 Correct 258 ms 24428 KB Output is correct
22 Correct 249 ms 23776 KB Output is correct
23 Correct 114 ms 19916 KB Output is correct
24 Correct 250 ms 25288 KB Output is correct
25 Correct 7 ms 1748 KB Output is correct
26 Correct 1 ms 340 KB Output is correct
27 Correct 1 ms 340 KB Output is correct
28 Correct 13 ms 3028 KB Output is correct
29 Correct 6 ms 1620 KB Output is correct
30 Correct 1 ms 340 KB Output is correct
31 Correct 1 ms 468 KB Output is correct
32 Correct 2 ms 468 KB Output is correct
33 Correct 1 ms 340 KB Output is correct
34 Correct 6 ms 1620 KB Output is correct
35 Correct 0 ms 340 KB Output is correct
36 Correct 1 ms 340 KB Output is correct
37 Correct 1 ms 340 KB Output is correct
38 Correct 1 ms 340 KB Output is correct
39 Correct 1 ms 340 KB Output is correct
40 Correct 218 ms 22536 KB Output is correct
41 Correct 253 ms 22604 KB Output is correct
42 Correct 240 ms 22512 KB Output is correct
43 Correct 114 ms 19284 KB Output is correct
44 Correct 111 ms 19228 KB Output is correct
45 Correct 246 ms 22444 KB Output is correct
46 Correct 248 ms 22260 KB Output is correct
47 Correct 242 ms 22484 KB Output is correct
48 Correct 107 ms 17652 KB Output is correct
49 Correct 207 ms 22676 KB Output is correct
50 Correct 248 ms 22320 KB Output is correct
51 Correct 236 ms 22312 KB Output is correct