#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define pii pair<int, int>
#define pll pair<ll, ll>
using namespace std;
const ll INF = 1e15;
int n;
vector<vector<pii>> adj;
vector<vector<int>> spadj;
vector<ll> dp;
vector<ll> sp, dist_u, dist_v;
ll dfs(int node) {
if (dp[node] != -1) return dp[node];
ll best = dist_v[node];
for (int dest : spadj[node]) {
best = min(best, dfs(dest));
}
return dp[node] = best;
}
vector<ll> dijkstra(int start_node) {
vector<ll> dist(n + 1, INF);
priority_queue<pll, vector<pll>, greater<pll>> q;
dist[start_node] = 0;
q.push({0, start_node});
while (!q.empty()) {
auto p = q.top();
q.pop();
ll curr_cost = p.first, node = p.second;
for (pii &edge : adj[node]) {
int dest = edge.first, edge_cost = edge.second;
if (dist[dest] > curr_cost + edge_cost) {
dist[dest] = curr_cost + edge_cost;
q.push({dist[dest], dest});
}
}
}
return dist;
}
int32_t main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int m, S, T, U, V;
cin >> n >> m >> S >> T >> U >> V;
adj.resize(n + 1);
spadj.resize(n + 1);
for (int i = 0; i < m; i++) {
int u, v, cost;
cin >> u >> v >> cost;
adj[u].push_back({v, cost});
adj[v].push_back({u, cost});
}
// shortest path, dist to u, dist to v
sp = dijkstra(S), dist_u = dijkstra(U), dist_v = dijkstra(V);
vector<bool> vis(n + 1, false);
// construct the shortest path
queue<int> q;
q.push(T);
while (!q.empty()) {
int node = q.front();
q.pop();
ll mn_dist = INF;
for (pii &edge : adj[node]) {
mn_dist = min(mn_dist, sp[edge.first]);
}
for (pii &edge : adj[node]) {
int dest = edge.first, edge_cost = edge.second;
if (sp[dest] + edge_cost == sp[node]) {
spadj[node].push_back(dest);
if (!vis[dest]) {
vis[dest] = true;
q.push(dest);
}
}
}
}
// dfs from T, calculate, reverse spadj and dfs from S and recalculate
ll best = dist_v[U];
dp = vector<ll>(n + 1, -1);
for (int i = 1; i <= n; i++) {
dfs(i);
best = min(best, dp[i] + dist_u[i]);
}
vector<vector<int>> tmp(n + 1);
// reverse the edges
for (int i = 1; i <= n; i++) {
for (int j : spadj[i]) {
tmp[j].push_back(i);
}
}
spadj = tmp;
dp = vector<ll>(n + 1, -1);
for (int i = 1; i <= n; i++) {
dfs(i);
best = min(best, dp[i] + dist_u[i]);
}
cout << best << '\n';
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
210 ms |
17508 KB |
Output is correct |
2 |
Correct |
226 ms |
18892 KB |
Output is correct |
3 |
Correct |
270 ms |
22820 KB |
Output is correct |
4 |
Correct |
194 ms |
17440 KB |
Output is correct |
5 |
Correct |
229 ms |
23668 KB |
Output is correct |
6 |
Correct |
242 ms |
21356 KB |
Output is correct |
7 |
Correct |
260 ms |
24440 KB |
Output is correct |
8 |
Correct |
251 ms |
23900 KB |
Output is correct |
9 |
Correct |
208 ms |
21828 KB |
Output is correct |
10 |
Correct |
177 ms |
21964 KB |
Output is correct |
11 |
Correct |
94 ms |
19892 KB |
Output is correct |
12 |
Correct |
251 ms |
21788 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
232 ms |
20004 KB |
Output is correct |
2 |
Correct |
251 ms |
20044 KB |
Output is correct |
3 |
Correct |
251 ms |
19760 KB |
Output is correct |
4 |
Correct |
246 ms |
20320 KB |
Output is correct |
5 |
Correct |
247 ms |
20396 KB |
Output is correct |
6 |
Correct |
244 ms |
23052 KB |
Output is correct |
7 |
Correct |
270 ms |
23472 KB |
Output is correct |
8 |
Correct |
251 ms |
19680 KB |
Output is correct |
9 |
Correct |
244 ms |
20516 KB |
Output is correct |
10 |
Correct |
241 ms |
19880 KB |
Output is correct |
11 |
Correct |
100 ms |
20808 KB |
Output is correct |
12 |
Correct |
259 ms |
23028 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
7 ms |
1080 KB |
Output is correct |
2 |
Correct |
1 ms |
332 KB |
Output is correct |
3 |
Correct |
1 ms |
332 KB |
Output is correct |
4 |
Correct |
11 ms |
2380 KB |
Output is correct |
5 |
Correct |
6 ms |
1356 KB |
Output is correct |
6 |
Correct |
1 ms |
332 KB |
Output is correct |
7 |
Correct |
1 ms |
460 KB |
Output is correct |
8 |
Correct |
2 ms |
460 KB |
Output is correct |
9 |
Correct |
1 ms |
332 KB |
Output is correct |
10 |
Correct |
6 ms |
1356 KB |
Output is correct |
11 |
Correct |
1 ms |
332 KB |
Output is correct |
12 |
Correct |
1 ms |
332 KB |
Output is correct |
13 |
Correct |
1 ms |
332 KB |
Output is correct |
14 |
Correct |
1 ms |
332 KB |
Output is correct |
15 |
Correct |
2 ms |
332 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
210 ms |
17508 KB |
Output is correct |
2 |
Correct |
226 ms |
18892 KB |
Output is correct |
3 |
Correct |
270 ms |
22820 KB |
Output is correct |
4 |
Correct |
194 ms |
17440 KB |
Output is correct |
5 |
Correct |
229 ms |
23668 KB |
Output is correct |
6 |
Correct |
242 ms |
21356 KB |
Output is correct |
7 |
Correct |
260 ms |
24440 KB |
Output is correct |
8 |
Correct |
251 ms |
23900 KB |
Output is correct |
9 |
Correct |
208 ms |
21828 KB |
Output is correct |
10 |
Correct |
177 ms |
21964 KB |
Output is correct |
11 |
Correct |
94 ms |
19892 KB |
Output is correct |
12 |
Correct |
251 ms |
21788 KB |
Output is correct |
13 |
Correct |
232 ms |
20004 KB |
Output is correct |
14 |
Correct |
251 ms |
20044 KB |
Output is correct |
15 |
Correct |
251 ms |
19760 KB |
Output is correct |
16 |
Correct |
246 ms |
20320 KB |
Output is correct |
17 |
Correct |
247 ms |
20396 KB |
Output is correct |
18 |
Correct |
244 ms |
23052 KB |
Output is correct |
19 |
Correct |
270 ms |
23472 KB |
Output is correct |
20 |
Correct |
251 ms |
19680 KB |
Output is correct |
21 |
Correct |
244 ms |
20516 KB |
Output is correct |
22 |
Correct |
241 ms |
19880 KB |
Output is correct |
23 |
Correct |
100 ms |
20808 KB |
Output is correct |
24 |
Correct |
259 ms |
23028 KB |
Output is correct |
25 |
Correct |
7 ms |
1080 KB |
Output is correct |
26 |
Correct |
1 ms |
332 KB |
Output is correct |
27 |
Correct |
1 ms |
332 KB |
Output is correct |
28 |
Correct |
11 ms |
2380 KB |
Output is correct |
29 |
Correct |
6 ms |
1356 KB |
Output is correct |
30 |
Correct |
1 ms |
332 KB |
Output is correct |
31 |
Correct |
1 ms |
460 KB |
Output is correct |
32 |
Correct |
2 ms |
460 KB |
Output is correct |
33 |
Correct |
1 ms |
332 KB |
Output is correct |
34 |
Correct |
6 ms |
1356 KB |
Output is correct |
35 |
Correct |
1 ms |
332 KB |
Output is correct |
36 |
Correct |
1 ms |
332 KB |
Output is correct |
37 |
Correct |
1 ms |
332 KB |
Output is correct |
38 |
Correct |
1 ms |
332 KB |
Output is correct |
39 |
Correct |
2 ms |
332 KB |
Output is correct |
40 |
Correct |
205 ms |
21256 KB |
Output is correct |
41 |
Correct |
207 ms |
21704 KB |
Output is correct |
42 |
Correct |
210 ms |
21728 KB |
Output is correct |
43 |
Correct |
115 ms |
24504 KB |
Output is correct |
44 |
Correct |
127 ms |
24932 KB |
Output is correct |
45 |
Correct |
256 ms |
26896 KB |
Output is correct |
46 |
Correct |
291 ms |
26564 KB |
Output is correct |
47 |
Correct |
199 ms |
21188 KB |
Output is correct |
48 |
Correct |
122 ms |
22852 KB |
Output is correct |
49 |
Correct |
171 ms |
20928 KB |
Output is correct |
50 |
Correct |
237 ms |
25500 KB |
Output is correct |
51 |
Correct |
245 ms |
26780 KB |
Output is correct |