Cod sursa(job #2344207)

Utilizator SamySam2099Irsai Samuel SamySam2099 Data 14 februarie 2019 21:17:50
Problema Algoritmul lui Dijkstra Scor 20
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.35 kb
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
ifstream f("dijkstra.in");
ofstream g("dijkstra.out");
#define Nmax 50005
int oo=(1<<30),n,m,D[Nmax];
vector <pair<int,int>> G[Nmax];
struct compare{
   bool operator()(int x,int y)
   {
       return D[x]<D[y];
   }
};
priority_queue<int,vector<int>,compare>Q;
bool viz[Nmax];
void read()
{
    f>>n>>m;
    for(int i=1;i<=m;i++)
    {
        int x,y,c;
        f>>x>>y>>c;
        G[x].push_back(make_pair(y,c));
    }
    for(int i=1;i<=n;i++)
    {
        D[i]=oo;
    }
    D[1]=0;
}
void Dijkstra(int nod_start)
{
   Q.push(nod_start);
   viz[nod_start]=1;
   while(!Q.empty())
   {
       int nod_curent = Q.top();
       Q.pop();
       for(int i=0;i<G[nod_curent].size();i++)
       {
           int vecin=G[nod_curent][i].first;
           int cost=G[nod_curent][i].second;
           if(D[nod_curent]+cost<D[vecin])
           {
               D[vecin]=D[nod_curent]+cost;
               if(!viz[vecin])
               {
                   Q.push(vecin);
                   viz[vecin]=1;
               }
           }
       }
   }

}
void show()
{
    for(int i=2;i<=n;i++)
    {
       if(D[i]!=oo) g<<D[i]<<' ';
       else g<<"0"<<' ';
    }
}
int main()
{
    read();
    Dijkstra(1);
    show();
    return 0;
}