Submission #1082874

#	Time	Username	Problem	Language	Result	Execution time	Memory
1082874		bundaunuoctuong	Commuter Pass (JOI18_commuter_pass)	C++14	15 / 100	427 ms	262144 KiB

commuter_pass

#include<bits/stdc++.h>
#define N 1000000
#define inf ll(1e18+7)
#define pii pair<int,int>
#define pll pair<ll,ll>
#define fi first
#define se second
#define pb push_back
#define all(x) x.begin(),x.end()
using namespace std;
typedef long long ll;
typedef double db;

const int M = 1e9+7;
int n,m,s,t,x,y;
vector<pll> adj1[N+3],adj2[N+3];
vector<int> tmp[N+3];
ll d[N+3];


void dijkstra1(){
    priority_queue<pll,vector<pll>,greater<pll>> qQ;
    fill(d+1,d+n+1,inf);
    d[s]=0;
    qQ.push({0,s});
    while(!qQ.empty()){
        ll du=qQ.top().fi;
        int u=qQ.top().se;
        qQ.pop();
        if(du!=d[u]) continue;
        for(auto P:adj1[u]){
            ll w=P.fi;
            int v=P.se;
            if(d[v]>d[u]+w){
                d[v]=d[u]+w;
                tmp[v].clear();
                tmp[v].pb(u);
                qQ.push({d[v],v});
            }
            else if(d[v]==d[u]+w)
                tmp[v].pb(u);
        }
    }
}
void dijkstra2(){
    priority_queue<pll,vector<pll>,greater<pll>> qQ;
    fill(d+1,d+n+1,inf);
    d[x]=0;
    qQ.push({0,x});
    while(!qQ.empty()){
        ll du=qQ.top().fi;
        int u=qQ.top().se;
        qQ.pop();
        if(du!=d[u]) continue;
        for(auto P:adj2[u]){
            ll w=P.fi;
            int v=P.se;
            if(d[v]>d[u]+w){
                d[v]=d[u]+w;
                qQ.push({d[v],v});
            }
        }
        for(auto P:adj1[u]){
            ll w=P.fi;
            int v=P.se;
            if(d[v]>d[u]+w){
                d[v]=d[u]+w;
                qQ.push({d[v],v});
            }
        }
    }
}

void DFS(int u, int p){
    for(auto v:tmp[u]) if(v!=p){
        adj2[u].pb({0,v});
        adj2[v].pb({0,u});
        DFS(v,u);
    }
}

void Solve(){
    dijkstra1();
    DFS(t,0);
    dijkstra2();
    cout << d[y];
}

void Inp(){
    cin >> n >> m >> s >> t >> x >> y;
    for(int u,v,w,i=1; i<=m; i++){
        cin >> u >> v >> w;
        adj1[u].pb({w,v});
        adj1[v].pb({w,u});
    }
}

int main(){
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    
    int T=1;
//  cin >> T;
    while(T--){
    Inp();
    Solve();
    }
}

• Subtask 1: 0 / 16
• Subtask 2: 15 / 15
• Subtask 3: 0 / 24
• Subtask 4: 0 / 45