由c++实现的二叉树的建立与遍历

#define MAX #define MAX 30 
#define NULL 0
#define OK 1
#define ERROR -1
#include <stdio.h> 
#include <malloc.h> 
typedef struct btnode 
{          
      char data; 
      struct btnode *lchild,*rchild; 
}bttree; 
typedef struct QNode
{ 
bttree *data; 
struct QNode *next; 
}QNode,*QueuePtr; 
typedef struct
{ 
QueuePtr front; 
QueuePtr rear; 
}LinkQueue; 

bttree* creat(bttree *t)
{ //以先序的顺序建立二叉链表的存储结构
  char ch;
  scanf("%c",&ch);
  if (ch=='#')
  t = NULL;
  else