BTree非递归

preorder

void PreOrder(BTNode* b)
{
	BTNode* p = b;
	SqStack* st;
	InitStack(st);
	if (b != NULL)
	{
		Push(st, p);
		while (!StackEmpty(st))
		{
			Pop(st,p);
			printf("%c", p->data);
			if (p->rchild != NULL)
			{
				Push(st,p->rchild);
			}
			if (p->lchild != NULL)
			{
				Push(st,p->lchild);
			}
		}
		printf("\n");
	}
	DestroyStack(st);
}

　　

void PreOrder1(BTNode* b)
{
	BTNode* p = b;
	SqStack* st;
	InitStack(st);
	while(p != NULL || !StackEmpty(st))
	{
		while (p != NULL)
		{
			printf("%c", p->data);
			Push(st,p);
			p = p->lchild;
		}
		if (!StackEmpty(st))
		{
			Pop(st, p);
			p = p->rchild;
		}
	}
	printf("\n");
	DestroyStack(st);
}

　　inorder

void InOrder(BTNode* b)
{
	BTNode* p = b;
	SqStack* st;
	InitStack(st);

	while (p != NULL || !StackEmpty(st))
	{
		while (p != NULL)
		{
			Push(st,p);
			p = p->lchild;
		}
		if (!StackEmpty(st))
		{
			Pop(st, p);
			printf("%c", p->data);
			p = p->rchild;
		}
	}
	printf("\n");
	DestroyStack(st);
}

　　postorder

void PostOrder(BTNode* b)
{
	BTNode* p = b;
	BTNode* r;
	SqStack* st;
	InitStack(st);
	bool flag;
	do
	{
		while (p != NULL)
		{
			Push(st,p);
			p = p->lchild;
		}
		r = NULL;
		flag= true;
		while (!StackEmpty(st) && flag)
		{
			GetTop(st, p);
			if (r == NULL&&p->rchild==NULL)
			{
				printf("%c", p->data);
				Pop(st, p);
				r = (BTNode*)malloc(sizeof(BTNode));
				r->data = p->data;
			}
			else if ((r != NULL&&p->rchild!=NULL)&&r->data==p->rchild->data)
			{
				printf("%c", p->data);
				Pop(st, p);
				r = (BTNode*)malloc(sizeof(BTNode));
				r->data = p->data;
			}
			else
			{
				p = p->rchild;
				flag = false;
			}
		}
	} while (!StackEmpty(st));
	printf("\n");
	DestroyStack(st);
}

　　层次遍历

typedef struct {
	BTNode data[MAXSIZE];
	int front, rear;
}SqQueue;

　　

void LevelOrder(BTNode* b)
{
	SqQueue* q;
	InitQueue(q);
	BTNode* p = b;
	enQueue(q,p);
	while (!QueueEmpty(q))
	{
		deQueue(q, p);
		printf("%c", p->data);
		if (p->lchild != NULL)
			enQueue(q, p->lchild);
		if (p->rchild != NULL)
			enQueue(q, p->rchild);
	}
}

　　利用层次遍历输出从根结点到每个叶子结点的逆路径

typedef struct {
	BTNode* pt;
	int parent;
}NodeType;

　　

typedef struct {
	NodeType data[MAXSIZE];
	int front, rear;
}QuType

　　

void AllPath2(BTNode* b)
{
	int k;
	BTNode* p;
	QuType* qu;
	InitQueue2(qu);
	NodeType* qelem = (NodeType*)malloc(sizeof(NodeType));
	qelem->pt = b;
	qelem->parent = -1;
	enQueue2(qu,qelem);
	while (!QueueEmpty2(qu))
	{
		deQueue2(qu, qelem);
		p = qelem->pt;
		if (p->lchild == NULL && p->rchild == NULL)
		{
			k = qu->front;
			while (qu->data[k].parent != -1)
			{
				printf("%c", qu->data[k].pt->data);
				k = qu->data[k].parent;
			}
			printf("%c\n", qu->data[k].pt->data);

		}
		if (p->lchild != NULL)
		{
			qelem->pt = p->lchild;
			qelem->parent = qu->front;
			enQueue2(qu, qelem);
		}
		if (p->rchild != NULL)
		{
			qelem->pt = p->rchild;
			qelem->parent = qu->front;
			enQueue2(qu, qelem);
		}
	}
}