public static void s(Node node){
if(node == null){
return ;
}
Queue<Node> queue = new LinkedList();
HashSet<Node> hashset = new HashSet();
queue.add(node);
hashset.add(node);
while(!queue.isEmpty()){
Node help = queue.poll();
for(Node next : help.nexts){
if(!hashset.contains(next)){
queue.add(next);
hashset.add(next)
}
}
}
}