线索二叉树

线索二叉树

节点

struct node
{
   int val;
   node *left,*right;
   bool lnode,rnode;
   node(){left = NULL,right = NULL,lnode = false,rnode = false;}
};

构造

void set_link(node *p,node *&pre)
{
	 if(p != NULL)
	 {
	 	set_link(p->left,pre);
	    if(p->left == NULL){
	    	p->left = pre;
	    	p->lnode = true;
		}
		//printf("%d\n",p->val);
		if(pre!=NULL&&pre->right == NULL)
		{  
			pre->right = p;
			pre->rnode = true;
		}
		pre = p;
		set_link(p->right,pre);
	 }
}
void Creat(node *T)
{
   node *pre = NULL;
   if(T!=NULL)
   {
     set_link(T,pre);
     pre->right = NULL;
     pre->rnode = true;
   }
}

求中序二叉树的第一个节点

node *Firstnode(node *p)
{   
	while(!p->lnode) p = p->left;
	return p;
}

求中序线索二叉树中节点p的后继节点

node *Nextnode(node *p)
{
	if(!p->rnode)
	  return Firstnode(p->right);
	return p->right;
}