Submission #407647

#	Time	Username	Problem	Language	Result	Execution time	Memory
407647		nguot	Commuter Pass (JOI18_commuter_pass)	C++14	100 / 100	608 ms	21744 KiB

commuter_pass

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define in ({int x=0;int c=getchar(),n=0;for(;!isdigit(c);c=getchar()) n=(c=='-');for(;isdigit(c);c=getchar()) x=x*10+c-'0';n?-x:x;})
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int rnd(int l,int r){return l+rng()%(r-l+1);}
#define fasty ios_base::sync_with_stdio(0),cin.tie(0),cout.tie(0);
#define fori(x,a,b) for (int x=a;x<=b;x++)
#define ford(x,a,b) for (int x=a;x>=b;x--)
#define forv(a,b) for(auto&a:b)
#define fi first
#define se second
#define pb push_back
#define ii pair<int,int>
#define all(a) a.begin(),a.end()
#define reset(f, x) memset(f, x, sizeof(f))
#define getbit(x,i) ((x>>i)&1)
#define batbit(x,i) (x|(1ll<<i))
#define tatbit(x,i) (x&~(1<<i))
#define gg exit(0);

const int maxn = 2e5 + 10;
int n,m,s,t,u,v;
vector<ii> ke[maxn];

vector<int> dij(int s)
{
    vector<int> f(n+5,1e15);
    priority_queue<ii,vector<ii>,greater<ii> > h;
    f[s] = 0;
    h.push({0,s});
    while(!h.empty())
    {
        ii tg = h.top();
        h.pop();
        int umin = tg.se,dmin = tg.fi;
        forv(v,ke[umin]) if(f[v.fi] > dmin + v.se)
        {
            f[v.fi] = dmin + v.se;
            h.push({f[v.fi],v.fi});
        }
    }
    return f;
}

// f[i] : dg di ngan nhat khi di toi uu tu u->i;
main()
{
    //freopen("task.inp","r",stdin);
    fasty;
   cin>>n>>m;
   cin>>s>>t>>u>>v;
   fori(i,1,m)
   {
       int x,y,c;cin>>x>>y>>c;
       ke[y].pb({x,c}),ke[x].pb({y,c});
   }
   vector<int> fs = dij(s);
   vector<int> ft = dij(t);
   vector<int> fu = dij(u);
   vector<int> fv = dij(v);

   int res = fu[v];
   fori(i,0,1)
   {
        vector<int> d(n+5,1e15),f(n+5,1e15);
        priority_queue<ii,vector<ii>,greater<ii> > h;
        h.push({0,s});
        d[s] = 0,f[s] = fu[s];
        while(!h.empty())
        {
            int umin,dmin;
            tie(dmin,umin) = h.top();
            h.pop();
            res = min(res,f[umin] + fv[umin]);
            forv(v,ke[umin]) if(fs[v.fi]+ft[v.fi]==fs[t])
            {
                f[v.fi] = min({f[v.fi],f[umin],fu[umin]});
                if(d[v.fi] > dmin + v.se)
                {
                    d[v.fi] = dmin + v.se;
                    h.push({d[v.fi],v.fi});
                }
            }
        }
        swap(fu,fv);
   }
   cout<<res;
}
/*
chon 1 dg di ngan nhat tu s->t,cho tat cac canh tren dg di nay = 0
sao cho dg di ngan nhat tu u->v la MIN
*/
//https://oj.uz/problem/view/JOI18_commuter_pass

Compilation message (stderr)

commuter_pass.cpp:47:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   47 | main()
      | ^~~~

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