Cod sursa(job #2181896)

Utilizator al3xionescuIonescu Alexandru al3xionescu Data 21 martie 2018 21:48:25
Problema Algoritmul lui Dijkstra Scor 40
Compilator cpp Status done
Runda Arhiva educationala Marime 1.23 kb
#include <cstdio>
const int maxn = 50001;
const int inf = 1<<30;
FILE *in = fopen("dijkstra.in","r"), *out=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 read() {
    fscanf(in, "%d %d", &n, &m);
    int x, y, z;
    for ( int i = 1; i <= m; ++i )
    {
        fscanf(in, "%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()
{
    read();
    dijkstra();
    for(int i=2;i<=n;i++)
        fprintf(out,"%d ",d[i]==inf?0:d[i]);
    fprintf(out, "\n");

    return 0;
}