BFS(G, s) {
  double inf = std::numeric_limits<double>::infinity();
  for (int i = 0; i < G.v.size(); i++) {
    if(G.v[i] != s) {
        G.v[i].color = "white";
        G.v[i].d = inf;
        G.v[i].parent = null;
    }
  }
  s.color = "gray";
  s.d = 0;
  s.parent = null;
  std::vector<Node> Q;
  Enqueue(Q,s);
  while (Q.size() > 0) {
    Node u = Dequeue(Q);
    std::vector<Node> AdjacentList = G.adj[u];
    for (int i = 0; i < AdjacentList.size(); i++) {
      if(AdjacentList[i].color == "white") {
        AdjacentList[i].color = "gray";
        AdjacentList[i].d = u.d + 1;
        AdjacentList[i].parent = u;
        Enqueue(Q, AdjacentList[i]);
      }
    }

  }

}