Cod sursa(job #1091323)

Utilizator ovidel95Ovidiu ovidel95 Data 25 ianuarie 2014 16:31:23
Problema Algoritmul lui Dijkstra Scor 20
Compilator cpp Status done
Runda Arhiva educationala Marime 1.26 kb
#include <fstream>
#define NMAX 20001
#define INF 1<<30
using namespace std;
ifstream f("dijkstra.in");
ofstream g("dijkstra.out");
int n,a[NMAX][NMAX],m;
void Dijkstra(int x0,int d[NMAX])
{
    int i, j, min, k, ok;
    int viz[NMAX];
    a[x0][x0]=0;
    for (i = 1; i<=n; i++)
    {
        d[i] = a[x0][i];
        viz[i] = 0;
    }
    viz[x0] = 1; ok = 1;
    while (ok)
    {
        min = INF;
        for (i = 1; i<=n; i++)
            if (!viz[i] && min>d[i])
            {
                min = d[i];
                k = i;
            }
        if (min != INF) {
            viz[k] = 1;
            for (i = 1; i<=n; i++)
               if (!viz[i] && d[i]>d[k]+a[k][i])
               {
                   d[i] = d[k]+a[k][i];
               }
        }
        else ok = 0;
    }
}
int main()
{
    f>>n>>m;
    int i,j,x,y,z;
    for(i=1;i<=m;i++)
    {
        f>>x>>y>>z;
        a[x][y]=z;
    }
    for(i=1;i<=n;i++)
        for(j=1;j<=n;j++)
            if(!a[i][j])
                a[i][j]=INF;
    int d[NMAX];
    Dijkstra(1,d);
    for(i=2;i<=n;i++)
        {   if(d[i]==INF)
                g<<0<<" ";
            else
                g<<d[i]<<" ";
        }
    f.close();
    g.close();
    return 0;
}