public static void dfsCat() {
		Stack<Integer> s = new Stack<Integer>();
		s.push(hcat);
		vcat[hcat] = true;
		while (!s.isEmpty()) {
			int cur = s.pop();
			for (int i = 0; i < gcat[cur].size(); i++) {
				int neigh = gcat[cur].get(i);
				if (!vcat[neigh]) {
					vcat[neigh] = true;
					s.push(neigh);
				}
			}
		}
	}