C语言中二叉树的非递归遍历，请教下这个程序怎么修改啊，万分感谢。。。

# include

# include

struct BTNode

{

int data;

struct BTNode * pLchild;//p是指针，L是左，child是孩子

struct BTNode * pRchild;

};

//函数声明

struct BTNode * CreateBTree(void);//创建树

void PreTraverseBTree(struct BTNode * pT);//先序遍历

void InTraverseBTree(struct BTNode * pT);//中序遍历

void PostTraverseBTree(struct BTNode * pT);//后续遍历

int main(void)

{

struct BTNode * pT = CreateBTree();

PreTraverseBTree(pT);

printf("\n");

InTraverseBTree(pT);

printf("\n");

PostTraverseBTree(pT);

return 0;

}

//创建树

struct BTNode * CreateBTree(void)

{

struct BTNode * pA = (struct BTNode * )malloc(sizeof(BTNode));

struct BTNode * pB = (struct BTNode * )malloc(sizeof(BTNode));

struct BTNode * pC = (struct BTNode * )malloc(sizeof(BTNode));

struct BTNode * pD = (struct BTNode * )malloc(sizeof(BTNode));

struct BTNode * pE = (struct BTNode * )malloc(sizeof(BTNode));

pA->data = 'A';

pB->data = 'B';

pC->data = 'C';

pD->data = 'D';

pE->data = 'E';

pA->pLchild = pB;

pA->pRchild = pC;

pB->pLchild = NULL;

pB->pRchild = NULL;

pC->pLchild = pD;

pC->pRchild = NULL;

pD->pLchild = NULL;

pD->pRchild = pE;

pE->pLchild = NULL;

pE->pRchild = NULL;

return pA;

}

//先序遍历

void PreTraverseBTree(struct BTNode * pT)

{ //先访问根节点，再先序访问左子树，最后先序访问右子树

if ( pT != NULL)

{

printf("%c\n",pT->data);//访问根节点

//pT->pLchild可以代表整个左子树

PreTraverseBTree(pT->pLchild);

PreTraverseBTree(pT->pRchild);

}

return;

}

//中序遍历

void InTraverseBTree(struct BTNode * pT)

{

if(pT != NULL )

{

if (NULL != pT->pLchild)

{

InTraverseBTree(pT->pLchild);

}

printf("%c\n",pT->data);

if (NULL != pT->pRchild)

{

InTraverseBTree(pT->pRchild);

}

}

return;

}

//后续遍历

void PostTraverseBTree(struct BTNode * pT)

{

if(pT != NULL )

{

if (NULL != pT->pLchild)

{

PostTraverseBTree(pT->pLchild);

}

if (NULL != pT->pRchild)

{

PostTraverseBTree(pT->pRchild);

}

printf("%c\n",pT->data);

}

return;

}

#include
#include
typedef struct bitnode
{
char data;
struct bitnode *lchild,*rchild;
}bitnode,*bitree;
bitree create_tree() //先序创建
{
char a;bitree root;
scanf("%c",&a);
fflush(stdin);
if(a=='#')return NULL;
else
{
root=(bitnode *)malloc(sizeof(bitnode));
root->data=a;
root->lchild=create_tree();
root->rchild=create_tree();
}
return root;
}

void inorder(bitree root)//中根遍历
{
bitree s[100];
int top=0;
while(root||top)
{
while(root)
{
s[++top]=root;root=root->lchild;
}
if(top)
{
putchar(s[top]->data);
root=s[top--]->rchild;
}
}
}
void main()
{
bitree root=NULL;
root=create_tree();//输入序列为先序遍历序列，＃代表空
inorder(root);
printf("\n");
}
//例如输入a(回车）b（回车）#（回车）#(回车）c(回车）#（回车）#(回车）输出bac

{
char a;bitree root;
scanf("%c",&a);
fflush(stdin);
if(a=='#')return NULL;
else
{
root=(bitnode *)malloc(sizeof(bitnode));
root->data=a;
root->lchild=create_tree();
root->rchild=create_tree();
}
return root;
}

void inorder(bitree root)//中根遍历
{
bitree s[100];
int top=0;
while(root||top)
{
while(root)
{
s[++top]=root;root=root->lchild;
}
if(top)
{
putchar(s[top]->dat