递归二叉树遍历

#include
#include "lyt0.h"
int main()
{
 BiTree T;
 cout<<"输入一串字符以'.'表示结束；"<<endl;
 CreateBiTree(T);
 cout<<"先序遍历："<<endl;
 PreOrderTraverse(T,PrintElement);
 cout<<endl;
 return 0;
}

//lyt0.h

#include
using namespace std;
#define OVERFLOW -2
#define OK 1
#define ERROR 0;
#define STACK_INIT_SIZE 100
#define STACKINCREMENT 10
typedef int Status;
Status PrintElement(char e);
typedef struct BiTNode
{
 char data;
 struct BiTNode *lchild,*rchild;
}BiTNode,*BiTree;
Status CreateBiTree(BiTree &T)
{
 char ch;
 scanf("%c",&ch);
 if(ch=='.')
  return 0;
 if(ch==' ')
  T=NULL;
 else
 {
  if(!(T=(BiTNode *)malloc(sizeof(BiTNode))))
   exit(OVERFLOW);
  T->data=ch;
  CreateBiTree(T->lchild);
  CreateBiTree(T->rchild);
 }
 return OK;
}
Status PreOrderTraverse(BiTree T,Status(* PrintElement)(char e))    //先序遍历
{
    if(T)
 {
  if(PrintElement(T->data))
   if(PreOrderTraverse(T->lchild,PrintElement))
    if(PreOrderTraverse(T->rchild,PrintElement))
     return OK;
    return ERROR;
 }
 else
  return OK;
}
Status PrintElement(char e)
{
   printf("%c",e);
   return OK;
}