二叉树的基本运算

#include "stdafx.h"
#include <stdio.h>
#include <stdlib.h>
#define OVERFLOW -2
typedef struct BiNode{
char data;
struct BiNode *lchild,*rchild;
}BiNode,*BT;
void createTree(BT &T)   //创建二叉树
{
char ch;
    scanf("%c",&ch);
    
if(ch=='#')
T=NULL;
else
{

if(!(T=(BT)malloc(sizeof(BiNode))))exit(OVERFLOW);

T->data=ch;
        createTree(T->lchild);
createTree(T->rchild);
}
return ;
}
void PreOrderTraverse(BT &T)   //递归先序遍历二叉树
{
if(T!=NULL)
{