Submission #1161241

#	Time	Username	Problem	Language	Result	Execution time	Memory
1161241		brover29	Commuter Pass (JOI18_commuter_pass)	C++17	100 / 100	286 ms	20240 KiB

commuter_pass

#include <bits/stdc++.h>
//qwerty47924692
using namespace std;
using ll = long long;
const ll N=1e5+29;
const string br="617283";
#define sz(a)(ll)a.size()
#define f first
#define s second
ll n,s,t,v,u,d[N],m,used[N],du[N],dv[N],ds[N],dt[N],p[N],dp[3][N];
vector<pair<ll,ll>>g[N];
ll cost[N];
void djikstra(ll s,ll *d){
    for(ll i=1;i<=n;i++){
        d[i]=1e18;
        used[i]=0;
    }
    d[s]=0;
    priority_queue<pair<ll,ll>>q;
    q.push({0,s});
    while(q.size()){
        ll v=q.top().s;
        q.pop();
        if(used[v])continue;
        used[v]=1;
        for(auto [to,w]:g[v]){
            if(d[to]>d[v]+w){
                d[to]=d[v]+w;
                q.push({-d[to],to});
            }
        }
    }

}bool cmp(ll a,ll b){
    return ds[a]<ds[b];
}
int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    cin>>n>>m>>s>>t>>v>>u;
    for(ll i=1;i<=m;i++){
        ll v,u,w;
        cin>>v>>u>>w;
        g[v].push_back({u,w});
        g[u].push_back({v,w});
    }
    djikstra(s,ds);
    djikstra(u,du);
    djikstra(v,dv);
    djikstra(t,dt);
    ll ans=0;
    ans=min({du[t]+ds[v],du[s]+dt[v],du[v]});
    iota(p+1,p+1+n,1);
    sort(p+1,p+1+n,&cmp);
    for(ll j=1;j<=n;j++){
        ll i=p[j];
        if(ds[i]+dt[i]!=ds[t])continue;
        dp[1][i]=du[i];
        dp[2][i]=dv[i];
        ans=min(ans,du[i]+dv[i]);
        for(auto [to,w]:g[i]){
            if(ds[to]+w==ds[i]){
                dp[1][i]=min(dp[1][i],dp[1][to]);
                dp[2][i]=min(dp[2][i],dp[2][to]);
                ans=min({ans,du[i]+dp[2][to],dv[i]+dp[1][to]});
            }
        }
    }
    cout<<ans;
}

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