// BFS()
// runs the BFS algorithm on the Graph G with source s,
// setting the color, distance, parent, and source fields of G accordingly
void BFS(Graph G, int s) {

	for (int i = 0; i < getOrder(G); i++) {
		if (s != getSource(G)) {
			G->color = WHITE;
			G->distance[i] = INF;
			G->parent[i] = NIL;
		}
	}

printf("completes initial for loop\n");

	G->source = s;

	G->color[s] = GRAY; // discover the source S
	G->distance[s] = 0;
	G->parent[s] = NIL;
	List list = newList();
printf("successfully initializes list = newList()\n");
	append(list, s); // equivalent to enqueue
printf("successfully appends to list\n");
	while (length(list) > 0) {

printf("started while(length(list) > 0)\n");
		// equivalent to dequeue
		int x = front(list);
		deleteFront(list);
printf("successfully deleteFront(list)\n");

		List getAdjacency = G->adjacency[x];
printf("successfully initializes getAdjacency\n");
		moveFront(getAdjacency);

		while (index(getAdjacency) != -1) {
			int y = get(getAdjacency);
printf("successfully assigns y\n");
			if (G->color[y] == WHITE) { // y is undiscovered
				G->color[y] = GRAY; // discover y
				G->distance[y] = G->distance[x] + 1;
				G->parent[y] = x;
				append(list, y);
printf("successfully appends y\n");
			}
			moveNext(getAdjacency);
		}
		G->color[x] = BLACK; // finish x
	}
	freeList(&list);
printf("successfully frees list\n");
}