Submission #340737

#	Time	Username	Problem	Language	Result	Execution time	Memory
340737		bigDuck	Commuter Pass (JOI18_commuter_pass)	C++14	15 / 100	446 ms	19692 KiB

commuter_pass

#include<bits/stdc++.h>
using namespace std;
#define INIT  ios_base :: sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
#define mp make_pair
#define pb push_back
#define ft first
#define sc second
#define ll long long
#define pii pair<int, int>
#define count_bits __builtin_popcount
#define int ll

int n, m, U, V, S, T;


vector<pii> g[100010];
bool v[100010];
int D[100010];
int previous[100010];


void dijkstra(int s, int fin){
previous[s]=0;
multiset<pii> ms;
ms.insert({0, s});

while(!ms.empty()){
    auto f=(*ms.begin()); ms.erase(ms.begin());
    int node=f.sc, d=f.ft;
    if(node==fin){
        break;
    }
    v[node]=true;
    for(pii pr:g[node]){
        int u=pr.ft, c=pr.sc;
        if(!v[u]){
            auto it=ms.find({D[u], u});
            if(it==ms.end()){
                D[u]=d+c;
                ms.insert({D[u], u});
                previous[u]=node;
            }
            else{
                if( (d+c)<D[u] ){
                    D[u]=d+c;
                    ms.erase(it);
                    ms.insert({D[u], u});
                    previous[u]=node;
                }
            }
        }
    }
}

for(int i=1; i<=n; i++){
    v[i]=false;
}

return ;
}



void reconstruct(int fin){
    int cr=fin;
    while(previous[cr]!=0){
        int u=previous[cr];
        g[u].pb({cr, 0}); g[cr].pb({u, 0});
        cr=u;
    }
}



int32_t main(){
INIT
cin>>n>>m;
cin>>S>>T;
cin>>U>>V;
for(int i=1; i<=m; i++){
    int a, b, c; cin>>a>>b>>c;
    g[a].pb({b,c}), g[b].pb({a, c});
}
dijkstra(S, T);
for(int i=1; i<=n; i++){
    D[i]=0;
}
reconstruct(T);
dijkstra(U, V);
cout<<D[V];

return 0;
}

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