帮忙修改一下，哪错了,该怎么解决

帮忙修改一下，哪错了
#include <stdio.h>
#include <malloc.h>

# define null 0
# define maxsize 100

typedef struct node 
{
  char data;
  struct node *lchild, *rchild;
}node, *bitree;

bitree Q[maxsize];  

bitree creat()
{
  char ch;
  int front,rear;
  bitree root,s;
  root = null;
  front = 1;
  rear = 0;
  ch = getchar();

  while (ch != '#')
  {
  s = null;
  if (ch != '@')
  {
  s = (bitree)malloc(sizeof(node));
  s->data = ch;
  s->lchild = null;
  s->rchild = null;
  }

  rear++;
  Q[rear] = s;
  if (rear == 1)
  {
  root = s;
  }
  else  
  {
  if(s && Q[front])
  if (rear%2 == 0)
  {
  Q[front]->lchild = s;  
  }
  else 
  {
  Q[front] ->rchild = s;  
  }

  if (rear%2 == 1) 
  {
  front++;  
  }
  }  

  ch = getchar();  
  }  

  return root;  
}

void Porderf(bitree root)
{int top=0; bitree p, s[100];
p=root;
while (p||top)
{while (p!=null)
printf("%d\t",p->data);
{s[top++]=p;
p=p->lchild;
}
if(top>0)
{p=s[--top];

p=p->rchild;
}
}
}
void main ()
{printf("请输入字符串");
bitree T=null;
T=creat();
getchar();
printf("先序遍历：");


Porderf(T);
getchar();
}

[解决办法]
把原始题目贴出来！