二叉树的遍历——BFS

void LayerOrder(node* root)
{
    
    
	queue<node*> Q;
	root->layer = 1;
	Q.push(root);
	while(!Q.empty())
	{
    
    
		node* now = Q.front();
		Q.pop();
		printf("%d ", now->data);
		if(now->lchild != NULL)
		{
    
    
			now->lchild->layer = now->layer + 1;
			Q.push(now->lchild); 
		}
		if(now->rchild != NULL)
		{
    
    
			now->rchild->layer = now->layer + 1;
			Q.push(now->rchild);
		}
	}
}