Submission #1253214

#	Time	Username	Problem	Language	Result	Execution time	Memory
1253214		quan606303	Commuter Pass (JOI18_commuter_pass)	C++17	100 / 100	190 ms	19756 KiB

commuter_pass

/*
 * @Author: RMQuan 
 * @Date: 2025-08-05 07:51:50 
 * @Last Modified by: RMQuan
 * @Last Modified time: 2025-08-05 10:27:02
 */
/*idea : 



*/
#include <bits/stdc++.h>
#define int long long
#define ll long long
#define INTMAX INT_MAX
#define INTMIN INT_MIN
#define LONGMAX LLONG_MAX
#define LONGMIN LLONG_MIN
#define fi first
#define se second
#define memfull(a,b) memset(a,b,sizeof(a));
#define endl '\n'
#define file(a) freopen(a".inp","r",stdin); freopen(a".out","w",stdout);
using namespace std;
const int MOD=1e9+7;
const int maxn=1e5+7;
const int inf=1e18;
vector<pair<int,int> > adj[maxn];
int dis[maxn][4],n,m;
bool vst[maxn];
void dij(int s,int id)
{
    for (int i=1;i<=n;i++)
    {
        dis[i][id]=inf;
        vst[i]=false;
    }
    priority_queue<pair<int,int>,vector<pair<int,int> >,greater<pair<int,int> > > q;
    q.push({0,s}); 
    dis[s][id]=0;
    while (q.size())
    {
        int u=q.top().se;
        q.pop();
        if (vst[u])continue;
        vst[u]=true;
        for (auto v:adj[u])
        {
            if (dis[v.fi][id]>dis[u][id]+v.se)
            {
                dis[v.fi][id]=dis[u][id]+v.se;
                q.push({dis[v.fi][id],v.fi});
            }
        }
    }
}
int S,T,U,V;
bool cmp(int x,int y)
{
    return dis[x][0]<dis[y][0];
}
int dp[maxn][2];
int32_t main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    cin>>n>>m>>S>>T>>U>>V;
    for (int i=1;i<=m;i++)
    {
        int u,v,w;
        cin>>u>>v>>w;
        adj[u].push_back({v,w});
        adj[v].push_back({u,w});
    }
    dij(S,0);
    dij(T,1);
    dij(U,2);
    dij(V,3);
    vector<int> topo;
    for (int i=1;i<=n;i++)topo.push_back(i);
    sort(topo.begin(),topo.end(),cmp);
    for (int i=1;i<=n;i++)dp[i][0]=dp[i][1]=inf;
    int ans=dis[V][2];
    for (auto i:topo)
    {
        if (dis[i][0]+dis[i][1]==dis[T][0])
        {
            dp[i][0]=dis[i][2];
            dp[i][1]=dis[i][3];
            for (auto v:adj[i])
            {
                if (dis[v.fi][0]+v.se+dis[i][1]==dis[T][0])
                {
                    dp[i][0]=min(dp[i][0],dp[v.fi][0]);
                    dp[i][1]=min(dp[i][1],dp[v.fi][1]);
                }
            }
            ans=min({ans,dp[i][0]+dis[i][3],dp[i][1]+dis[i][2]});                                                       
        }
    }
    cout<<ans;
    return 0;
}

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