Cod sursa(job #890446)

Utilizator VladutZ94FMI Chichirau Vlad Vasile VladutZ94 Data 25 februarie 2013 09:03:16
Problema Algoritmul lui Dijkstra Scor 40
Compilator cpp Status done
Runda Arhiva educationala Marime 1.17 kb
#include <cstdio>

const int maxn=50001;
const int inf=1 << 30;

FILE *f=fopen("dijkstra.in","r"), *g=fopen("dijkstra.out","w");

struct graf
{
    int nod, cost;
    graf *next;
};

int n,m;
graf *a[maxn];
int d[maxn], q[maxn];

void add(int where, int what, int cost)
{
    graf *q= new graf;
    q->nod=what;
    q->cost=cost;
    q->next=a[where];
    a[where]=q;
}

void citire()
{
    fscanf(f,"%d%d",&n,&m);
    int x,y,z;
    for(int i=1;i<=m;i++)
    {
        fscanf(f,"%d%d%d",&x,&y,&z);
        add(x, y, z);
    }
}

void dijkstra()
{

    for(int i=2;i<=n;i++)
        d[i]=inf;
    int min, pmin=0;
    for(int i=1;i<=n;++i)
    {
        min=inf;
        for(int j=1;j<=n;++j)
            if(d[j]<min && !q[j])
                min=d[j], pmin=j;
        q[pmin]=1;
        graf *t=a[pmin];

        while(t)
        {
            if(d[t->nod]>d[pmin]+t->cost)
                d[t->nod]=d[pmin]+t->cost;

            t=t->next;
        }
    }
}

int main()
{
    citire();
    dijkstra();
    for ( int i = 2; i <= n; ++i )
        fprintf(g, "%d ", d[i] == inf ? 0 : d[i]);
    fprintf(g, "\n");

    return 0;
}