#include "dijkstra.h"

#include "heap.h"

#include <math.h>

#include <stdlib.h>

#include <stdio.h>

double* distances;

int compare(graph* g, unsigned int i, unsigned int j) {

if(g->nodes[i].distance == g->nodes[j].distance) { return 0; }

if(g->nodes[i].distance > g->nodes[j].distance) { return 1; }

return -1;

}

void dijkstra(graph* g, unsigned int source) {

unsigned int u, v, edge_count;

node *n, *d;

edge *e;

heap *Q;

g->nodes[source].distance = 0;

Q = heap_make(compare, g);

while(!heap_is_empty(Q)) {

u = heap_delete_min(Q);

n = &g->nodes[u];

edge_count = n->edge_count;

for(v = 0; v < edge_count; v++) {

e = &n->edges[v];

d = &g->nodes[e->destination];

if(d->distance > n->distance + e->weight) {

/*

Relajo los vertices

*/

d->distance = n->distance + e->weight;

/*

Actualizo el nodo con la distancia optima a este

*/

d->previous = u;

/*

Actualizo la cola de prioridad (el vertice solo puede

haber subido en prioridad, entonces solo hago heapify-up

*/

heap_heapify_up(Q, d->heap_index);

}

}

}

heap_destroy(Q);

}