Submission #944341

#	Time	Username	Problem	Language	Result	Execution time	Memory
944341		quan606303	Commuter Pass (JOI18_commuter_pass)	C++14	100 / 100	289 ms	21892 KiB

commuter_pass

///0-0 : what is your motivation, quan606303?
///quan606303 : Hutao
/*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;
vector <pair<int,int> > adj[maxn];
int n,m,s,t,u,v,diS[maxn],diT[maxn],diU[maxn],diV[maxn];
void dijstra(int x,int *dis)
{
    priority_queue<pair<int,int>,vector<pair<int,int> > ,greater<pair<int,int> > > q;
    bool vst[maxn];
    for (int i=1;i<=n;i++)
    {
        dis[i]=1e18;
        vst[i]=false;
    }
    dis[x]=0;
    q.push({0,x});    
    while (q.size())
    {
        int k=q.top().se;
        q.pop();
       // cout<<u<<endl;
        if (vst[k])continue;
        vst[k]=true;
        for (auto i:adj[k])
        {
            if (dis[i.fi]>dis[k]+i.se)
            {
                dis[i.fi]=dis[k]+i.se;
                q.push({dis[i.fi],i.fi});
            }
        }
    }
}
int dp1[maxn],dp2[maxn];
vector <int> vt;
bool cmp(int x,int y)
{
    return diS[x]<diS[y];
}
int32_t main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    //file("PathLib");
    cin>>n>>m>>s>>t>>u>>v;
    for(int i=1;i<=m;i++)
    {
        int x,y,w;
        cin>>x>>y>>w;
        adj[x].push_back({y,w});
        adj[y].push_back({x,w});    
    }
    dijstra(s,diS);
    dijstra(t,diT);
    dijstra(u,diU);
    dijstra(v,diV);
    for (int i=1;i<=n;i++)vt.push_back(i);
    sort(vt.begin(),vt.end(),cmp);
   // cout<<diS[4]<<" "<<diT[4]<<" "<<diS[t]<<endl;
    int res=diU[v];
    for (auto x:vt)
    {
        if (diS[x]+diT[x]==diS[t])
        {
            dp1[x]=diU[x];
            dp2[x]=diV[x];
            for (auto y:adj[x])
            {
                if(diS[y.fi] + y.se == diS[x]){
                    dp1[x]=min(dp1[x],dp1[y.fi]);
                    dp2[x]=min(dp2[x],dp2[y.fi]);
                }
            }
            //cout<<x<<" "<<dp1[x]<<" "<<dp2[x]<<endl;
         res = min({res, dp1[x] + diV[x], dp2[x] + diU[x]});
        }
        
         //cout<<res<<endl;
    }
    cout<<res;
    return 0;
}

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