Cod sursa(job #1091349)

Utilizator ovidel95Ovidiu ovidel95 Data 25 ianuarie 2014 17:04:26
Problema Algoritmul lui Dijkstra Scor 20
Compilator cpp Status done
Runda Arhiva educationala Marime 2.36 kb
#include <fstream>
#define NMAX 50001
#define INF 1<<30
using namespace std;
ifstream f("dijkstra.in");
ofstream g("dijkstra.out");
int n,m;
struct Lista
{
    int x,y,c;
    Lista *urm;
};
void Dijkstra(int x0,int d[NMAX],Lista *p)
{
    int i, j, min, k, ok,s;
    int viz[NMAX];
    Lista *prim;
    for (i = 1; i<=n; i++)
    {
        prim=p->urm;
        s=INF;
        while(prim!=NULL)
        {
            if(prim->x==x0&&prim->y==i)
                {
                    s=prim->c;
                    prim=NULL;
                }
            else
                prim=prim->urm;
        }
        d[i] = s;
        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++)
            {
                s=INF;
                prim=p->urm;
                while(prim!=NULL)
                {
                    if(prim->x==k&&prim->y==i)
                        {
                            s=prim->c;
                            prim=NULL;
                        }
                    else
                        prim=prim->urm;
                }
               if (!viz[i] && d[i]>d[k]+s)
               {
                   d[i] = d[k]+s;
               }
            }
        }
        else ok = 0;
    }
}
void afisare(Lista *p)
{
    p=p->urm;
    while (p!=NULL)
    {
        g<<p->x<<" ";
        p=p->urm;
    }
}
int main()
{
    f>>n>>m;
    int i,j,x,y,z;
    Lista *ultim,*nou,*prim;
    prim=new Lista;
    prim->urm=NULL;
    ultim=prim;
    for(i=1;i<=m;i++)
    {
        nou=new Lista;
        f>>x>>y>>z;
        nou->x=x;
        nou->y=y;
        nou->c=z;
        nou->urm=NULL;
        ultim->urm=nou;
        ultim=nou;
    }
        //a[x][y]=z;

    //afisare(prim);
    /*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,prim);
    for(i=2;i<=n;i++)
        {   if(d[i]==INF)
                g<<0<<" ";
            else
                g<<d[i]<<" ";
        }
    f.close();
    g.close();
    return 0;
}