Submission #1180753

#	Time	Username	Problem	Language	Result	Execution time	Memory
1180753		asli_bg	Commuter Pass (JOI18_commuter_pass)	C++20	39 / 100	267 ms	20796 KiB

commuter_pass

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

#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;

#define int long long
//#define int double

typedef pair<int,int> pii;
typedef vector<pii> vii;
typedef vector<int> vi;
typedef vector<bool> vb;

#define FOR(i,a) for(int i=0;i<(a);i++)
#define FORE(i,a,b) for(int i=(a);i<(b);i++)

#define all(x) x.begin(),x.end()
#define fi first
#define se second
#define pb push_back
#define sp <<" "<<

#define cont(x) for(auto el:x) cout<<el<<' ';cout<<endl;
#define contp(x) for(auto el:x) cout<<el.fi<<'-'<<el.se<<' ';cout<<endl;

#define DEBUG(x) cout<<#x sp x<<endl;
#define carp(x,y) ((x%MOD)*(y%MOD))%MOD
#define topla(x,y) ((x%MOD)+(y%MOD))%MOD
#define mid (l+r)/2

const int MAXN=1e5+5;
const int MOD=1e9+7;
const int INF=1e18;

int n,m,s,t,u,v;
vii adj[MAXN];

pii tut[MAXN];

void dij(int bas,bool f){
    set<pii> s;
    s.insert({0,bas});

    if(f) tut[bas].fi=0;
    else tut[bas].se=0;

    while(!s.empty()){
        auto el=*s.begin();
        s.erase(el);

        int nd=el.se;

        for(auto [kom,cost]:adj[nd]){
            if(f){ //u
                if(tut[kom].fi>tut[nd].fi+cost){
                    if(s.count({tut[kom].fi,kom})) s.erase({tut[kom].fi,kom});
                    tut[kom].fi=tut[nd].fi+cost;
                    s.insert({tut[kom].fi,kom});
                }
            }
            else{ //v
                if(tut[kom].se>tut[nd].se+cost){
                    if(s.count({tut[kom].se,kom})) s.erase({tut[kom].se,kom});
                    tut[kom].se=tut[nd].se+cost;
                    s.insert({tut[kom].se,kom});
                }
            }
        }
    }
}

pii tut2[MAXN]; //s'den başlayıp bana gelen min pathtteki 
                //{u'ya en yakın, v'ye en yakın mesafe}
int dd[MAXN];
int p[MAXN];

void dij2(int bas){
    set<pii> s;
    s.insert({0,bas});
    dd[bas]=0;

    while(!s.empty()){
        auto el=*s.begin();
        s.erase(el);

        int nd=el.se;

        for(auto [kom,cost]:adj[nd]){
            if(dd[kom]>dd[nd]+cost){
                if(s.count({dd[kom],kom})) s.erase({dd[kom],kom});
                p[kom]=nd;
                dd[kom]=dd[nd]+cost;
                s.insert({dd[kom],kom});
                tut2[kom].fi=min(tut[kom].fi,tut2[nd].fi);
                tut2[kom].se=min(tut[kom].se,tut2[nd].se);
            }
            else if(dd[kom]==dd[nd]+cost){
                int bir=min(tut2[nd].fi,tut[kom].fi);
                int iki=min(tut2[nd].se,tut[kom].se);
                if(bir+iki<tut2[kom].fi+tut2[kom].se){
                    p[kom]=nd;
                    tut2[kom].fi=bir;
                    tut2[kom].se=iki;
                    s.insert({dd[kom],kom});
                }
            }
        }
    }
}

signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    
    cin>>n>>m;
    cin>>s>>t;
    cin>>u>>v;

    FOR(i,m){
        int a,b,c;
        cin>>a>>b>>c;
        adj[a].pb({b,c});
        adj[b].pb({a,c});
    }

    FORE(i,1,n+1) tut[i].fi=tut[i].se=dd[i]=tut2[i].fi=tut2[i].se=INF;

    //u ve v'den herkese sp bul
    dij(u,true);
    dij(v,false);

    //FORE(i,1,n+1) cout<<"here" sp i sp tut[i].fi sp tut[i].se<<endl;

    dij2(s);

    vb mark(n+1,false);

    int x=t;
    while(x!=s){
        mark[x]=true;
        x=p[x];
    }
    mark[s]=true;

    int ans=0;
    if(!mark[u] and !mark[v]){
        ans=min(tut[u].se,tut2[t].fi+tut2[t].se);
    }
    else if(!mark[v]){
        ans=tut2[t].se;
    }
    else if(!mark[u]){
        ans=tut2[t].fi;
    }

    cout<<ans<<endl;
}   

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