中序线索化及遍历

终于把二叉树搞完了

跟着王道的课走了几遍，终于把中序线索树的生成和遍历搞定了，这玩意做题思路还挺清晰，写代码真是折磨人啊

#include<stdio.h>
#include<stdlib.h>

typedef struct Node
{
	int data;
	struct Node* pleft;
	struct Node* pright;
	int tagleft;
	int tagright;
}node, * pnode;

node *pre = NULL;

void inthread(pnode T)
{
	if (T != NULL)
	{
		inthread(T->pleft);
		visit(T);
		inthread(T->pright);
	}
}

void visit(pnode p)//中序线索化
{
	if (p->pleft==NULL)
	{
		p->pleft = pre;
		p->tagleft = 1;
	}
	if (pre != NULL && pre->tagright==NULL)
	{
		pre->pright = p;
		pre->tagright = 1;
	}
	pre = p;
	//此时pre指向最后一个节点
	//在调用时，最后需要将pre的右指针置为null
}

pnode findnext(pnode p)
{
	if (p->tagright == 1)//p没有右节点，右节点存放的就是下个节点
	{
		return p->pright;
	}
	else
	{
		while (p->tagleft == 0)p = p->pleft;//找到最左的节点
	}
	return p;
}