Cod sursa(job #2493864)

Utilizator Botzki17Botocan Cristian-Alexandru Botzki17 Data 17 noiembrie 2019 08:34:13
Problema Algoritmul lui Dijkstra Scor 20
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.39 kb
#include <fstream>
#include <vector>
#include <queue>
#include <climits>
using namespace std;
ifstream fin("dijkstra.in");
ofstream fout("dijkstra.out");
const int NMAX = 50000;
const int INF = INT_MAX;
struct graf
{
   int nod, cost;
   bool operator < (const graf &a) const
   {
       return cost > a.cost;
   }
};
int dist[NMAX+5];
vector <graf> G[NMAX+5];
priority_queue <graf> pq;
void Dijkstra()
{
    int i;
    graf a, b;
    a.nod = 1;
    a.cost =0;
    pq.push(a);
    while(!pq.empty())
    {
        a = pq.top();
        pq.pop();
        if(a.cost > dist[a.nod])
            continue;
        for(i=0;i<G[a.nod].size();i++)
        {
           b.nod = G[a.nod][i].nod;
           b.cost = G[a.nod][i].cost;
           if(dist[a.nod] + b.cost < dist[b.nod])
           {
              dist[b.nod] = dist[a.nod] + b.cost;
              b.cost = dist[b.nod];
              pq.push(b);
           }
        }
    }
}
int main()
{
    int n, m, i, a, b, c;
    graf aux;
    fin>>n>>m;
    dist[1] = 0;
    for(i=2;i<=n;i++)
        dist[i] = INF;
    for(i=1;i<=m;i++)
    {
        fin>>a>>b>>c;
        aux.cost = c;
        aux.nod = b;
        G[a].push_back(aux);
    }
    Dijkstra();
    for(i=2;i<=n;i++)
    {
         if(dist[i] == INF)
            fout<<-1<<" ";
         else
            fout<<dist[i]<<" ";
    }
    return 0;
}