C++非递归创建访问二叉树

#include<iostream>
using namespace std;
typedef char TElemType;
#define maxSize 20

typedef struct node {
	TElemType data;
	struct node*lchild, *rchild;
}BinNode,*BinTree;

typedef BinNode* SElemType;

void CreateTree(BinNode*&BT, TElemType ch[], int&n)
{
	TElemType c = ch[n++];
	if (c == ';')return;
	if (c == '#') {
		BT = NULL;
		return;
	}
	else {
		BT = new BinNode;
		BT->data = c;
		CreateTree(BT->lchild, ch, n);
		CreateTree(BT->rchild, ch, n);
	}
}

void PrintTree(BinNode*BT)
{
	if (BT != NULL)
	{
		cout << BT->data << ' ';
		PrintTree(BT->lchild);
		PrintTree(BT->rchild);
	}
}

//利用栈实现先序遍历的非递归算法
void PreOrder(BinTree BT)
{
	SElemType S[maxSize];
	int top = -1;
	BinNode*p = BT;
	do {
		while (p != NULL)
		{
			cout << p->data << " ";
			S[++top] = p;
			p = p->lchild;
		}
		if (top != -1)
		{
			p = S[top--];
			p = p->rchild;
		}
	} while (top != -1 || p != NULL);
}

//栈中序遍历的非递归算法
void InOrder(BinTree BT)
{
	SElemType S[maxSize];
	int top = -1;
	BinNode*p = BT;
	do {
		while (p != NULL)
		{
			S[++top] = p;
			p = p->lchild;
		}
		p = S[top--];
		if (p != NULL)
		{
			cout << p->data << ' ';
			p = p->rchild;
		}
	} while (top != -1 || p != NULL);
}

//二叉树后序遍历的非递归算法
void PostOrder(BinTree BT)
{
	SElemType S[maxSize];
	int top = -1;
	BinNode*p = BT,*pre=NULL;
	do {
		while (p != NULL)
		{
			S[++top] = p;
			p = p->lchild;
		}
		p = S[top];
		if (p->rchild != NULL && p->rchild != pre)
			p = p->rchild;
		else {
			cout << p->data;
			pre = p;p = NULL;
			top--;
		}
	}

}

void CreateBinTree_pre_In(BinNode*&t, TElemType pre[], TElemType In[], int s1, int t1, int s2, int t2)
{
	if (s1 <= t1)
	{
		t = new BinNode;
		t->data = pre[s1];t->lchild = NULL;t->rchild = NULL;
		int i;
		for (i = s2;i <= t2;i++)
		{
			if (pre[s1] == In[i])break;
		}
		CreateBinTree_pre_In(t->lchild, pre, In, s1 + 1, s1 - s2 + i, s2, i - 1);
		CreateBinTree_pre_In(t->rchild, pre, In, s1 - s2 + i + 1, t1, i + 1, t2);
	}
}


int main()
{
	BinTree BT;
	BinTree Tree;
	int n = 0;
	TElemType ch[] = "ABC##D#E###";
	TElemType pre[] = "ABHFDECKG";
	TElemType In[] = "HBDFAEKCG";
	CreateBinTree_pre_In(Tree, pre, In, 0, 9, 0, 9);
	CreateTree(BT, ch,n);
	PreOrder(BT);
	cout << endl;
	InOrder(BT);
	cout << endl;
	PreOrder(Tree);

	system("pause");
}