void bfs(Graph *graph, Node *s, Operation *op)
{
    // TOOD: implement the BFS algorithm on the graph, starting from the node s
    // at the end of the algorithm, every node reachable from s should have the color BLACK
    // for all the visited nodes, the minimum distance from s (dist) and the parent in the BFS tree should be set
    // for counting the number of operations, the optional op parameter is received
    // since op can be NULL (when we are calling the bfs for display purposes), you should check it before counting:
    // if(op != NULL) op->count();

    int poz = 0;
    for (int w = 0; w < graph->nrNodes; w++) {
        if (graph->v[w] == s) {
            graph->v[w]->color = 1;
            break;
        }
    }

    list<Node*> coada;
    coada.push_back(s);

    while (!coada.empty()) {
        Node* u = coada.front();
        coada.pop_front();

        for (int w = 0; w < u->adjSize; w++) {
            if (u->adj[w]->color == COLOR_WHITE) {
                for (int j = 0; j < graph->nrNodes; j++) {
                    if (graph->v[j] == u->adj[w]) {
                        poz = j;
                        break;
                    }
                }
                u->color = COLOR_GRAY;
                //graph->v[poz]->color = COLOR_GRAY;
                graph->v[poz]->dist = u->dist + 1;
                graph->v[poz]->parent = u;
                coada.push_back(u->adj[w]);
            }
        }

        graph->v[poz]->color = COLOR_BLACK;
        u->color = COLOR_BLACK;
    }
}