Submission #1279739

#	Time	Username	Problem	Language	Result	Execution time	Memory
1279739		hanguyendanghuy	Commuter Pass (JOI18_commuter_pass)	C++20	0 / 100	1899 ms	327680 KiB

commuter_pass

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pb push_back
#define fi first
#define se second
constexpr ll MAXN=1e5+5,MAXV=3e5,MOD=1e9+7,INF=1e18;
ll n,m,i,j,p,k,ans,dem,st,en,dist[3][MAXN],S,T,U,V,len[MAXN],miV[MAXN],miU[MAXN];
vector<pair<ll,ll>> adj[MAXN];
void dij(ll st,ll type){
    fill(dist[type]+1,dist[type]+n+1,INF);
    priority_queue<pair<ll,ll>> q;
    dist[type][st]=0;
    q.push({0,st});
    while(q.size()){
        auto k=q.top();q.pop();
        if(-k.fi>dist[type][k.se]) continue;
        for(auto x:adj[k.se]){
            if(dist[type][x.fi]>-k.fi+x.se){
                dist[type][x.fi]=-k.fi+x.se;
                q.push({-dist[type][x.fi],x.fi});
            }
        }
    }
}
void solve(ll st,ll en){
    for(i=1;i<=n;i++) len[i]=miV[i]=miU[i]=INF;
    len[st]=0;
    miU[st]=dist[1][st];
    miV[st]=dist[2][st];
    priority_queue<pair<ll,int>> q;
    q.push({0,st});
    while(q.size()){
        auto k=q.top();q.pop();
        if(-k.fi>len[k.se]) continue;
        for(auto x:adj[k.se]){
            if(len[x.fi]>-k.fi+x.se){
                len[x.fi]=-k.fi+x.se;
                miU[x.fi]=min(dist[1][x.fi],miU[k.se]);
                miV[x.fi]=min(dist[2][x.fi],miV[k.se]);
                q.push({-len[x.fi],x.fi});
            }
            else if(len[x.fi]==-k.fi+x.se){
                if(min(dist[1][x.fi],miU[k.se])+min(dist[2][x.fi],miV[k.se])<miU[k.se]+miV[k.se]){
                    miU[x.fi]=min(dist[1][x.fi],miU[k.se]);
                    miV[x.fi]=min(dist[2][x.fi],miV[k.se]);
                    q.push({-len[x.fi],x.fi});
                }
            }
        }
    }
    if(len[en]!=INF){
        ans=min(ans,miU[en]+miV[en]);
    }
}
int main(){
    ios::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    cin>>n>>m>>S>>T>>U>>V;
    for(i=1;i<=m;i++){
        ll u,v,c;
        cin>>u>>v>>c;
        adj[u].pb({v,c});
        adj[v].pb({u,c});
    }
    dij(U,1);
    dij(V,2);
    ans=dist[1][V];
    solve(S,T);
    solve(T,S);
    cout<<ans;
}

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