| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 330872 | evn | Commuter Pass (JOI18_commuter_pass) | C++14 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
using namespace std;
#define f first
#define s second
#define pb push_back
#define mp make_pair
typedef long long ll;
typedef pair<ll, ll> pii;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
template<class T> using oset=tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define int long long
vector<pii> adj[100005];
set<int> parents[100005];
ll dijkstra[100005];
ll dijkstra2[100005];
bool vis[100005];
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int N, M, S, T, U, V;
cin >> N >> M >> S >> T >> U >> V; S--; T--; U--; V--;
for(int i = 0; i < M;i ++){
ll a, b, c;
cin >> a >> b >> c;
a--; b--;
adj[a].pb({b,c});
adj[b].pb({a,c});
}
//run yikstras once
for(int i =0; i < N;i ++){
dijkstra[i] = 1e18;
dijkstra2[i] = 1e18;
}
dijkstra[S] = 0;
priority_queue<pii, vector<pii>, greater<pii>> pq;
pq.push({0,S});
while(!pq.empty()){
pii curr = pq.top(); pq.pop();
if(dijkstra[curr.s] != curr.f)continue;
for(auto it : adj[curr.s]){
ll next = it.f;
ll weight = it.s;
if(weight + dijkstra[curr.s] == dijkstra[next]){
parents[next].insert(curr.s);
}
if(weight + dijkstra[curr.s] < dijkstra[next]){
parents[next].clear();
parents[next].insert(curr.s);
dijkstra[next] = weight + dijkstra[curr.s];
pq.push({dijkstra[next], next});
}
}
}
queue<int> q;
q.push(T);
while(!q.empty()){
int top = q.front(); q.pop();
for(int u : parents[top]){
if(!vis[u]){
adj[u].pb({top,0});
adj[top].pb({u,0});
vis[u] = true;
q.push(u);
}
}
}
dijkstra2[U] = 0;
pq.push({0, U});
while(!pq.empty()){
pii curr = pq.top(); pq.pop();
if(dijkstra2[curr.s] != curr.f)continue;
for(auto it : adj[curr.s]){
ll next = it.f;
ll weight = it.s;
if(weight + dijkstra2[curr.s] < dijkstra2[next]){
//cout << curr.s << " " << next << " " << weight << '\n';
dijkstra2[next] = weight+dijkstra2[curr.s];
pq.push({dijkstra2[next], next});
}
}
}
cout << dijkstra2[V] << '\n';
}