Submission #630860

#	Time	Username	Problem	Language	Result	Execution time	Memory
630860		Abrar_Al_Samit	Commuter Pass (JOI18_commuter_pass)	C++17	100 / 100	327 ms	21048 KiB

commuter_pass

#include<bits/stdc++.h>
using namespace std;

const int MX = 1e5 + 5;
const long long INF = 1e18;

vector<pair<int,int>>g[MX];
int n, m, s, t, u, v;
vector<long long>d(MX, INF), d2(MX, INF), dist(MX, INF), dist2(MX, INF);
vector<long long>dp(MX, INF), dp2(MX, INF);
void PlayGround() {
  cin>>n>>m>>s>>t>>u>>v;

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

  for(int sc : {u, v}) {
    d[sc] = 0;

    priority_queue<pair<long long, int>>pq;
    pq.emplace(0, sc);
    while(!pq.empty()) {
      long long cost;
      int node;
      tie(cost, node) = pq.top(); pq.pop();
      cost = -cost;
      if(cost!=d[node]) continue;

      for(auto e : g[node]) if(e.second+cost<d[e.first]) {
        d[e.first] = cost+e.second;
        pq.emplace(-d[e.first], e.first);
      }
    }
    swap(d, d2);
  }

  for(int sc : {s, t}) {
    dist[sc] = 0;
    dp[sc] = d2[sc];
    priority_queue<pair<long long, int>>pq;
    pq.emplace(0, sc);

    while(!pq.empty()) {
      long long cost; int node;
      tie(cost, node) = pq.top(); pq.pop();
      cost = -cost;
      if(cost!=dist[node]) continue;

      for(auto e : g[node]) {
        if(e.second+cost<dist[e.first]) {
          dist[e.first] = cost+e.second;
          dp[e.first] = min(dp[node], d2[e.first]);
          pq.emplace(-dist[e.first], e.first);
        } else if(e.second+cost==dist[e.first]) {
          dp[e.first] = min(dp[e.first], dp[node]);
        }
      }
    }
    swap(dp, dp2);
    swap(dist, dist2);
  }

  long long ans = d[v];
  for(int i=1; i<=n; ++i) if(dist[i]+dist2[i]==dist[t]) {
    ans = min(ans, d[i]+min(dp[i], dp2[i]));
  }
  cout<<ans<<'\n';
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  PlayGround();
  return 0;
}

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