something about binary tree - c

Question

This code is about binary tree.
It can work well.
But after I press the enter key and get the correct answer,it turns out stopping working.WHY？
This is the answer
source code:
#include <stdio.h>
#include <stdlib.h>
typedef struct BiTNode
{
char data;
struct BiTNode* rchild;
struct BiTNode* lchild;
}BiTNode;
typedef BiTNode* BiTree;
int CreateBiTree(BiTree *T);
void Visit(BiTree T);
void PreOrder(BiTree T);
void InOrder(BiTree T);
void PostOrder(BiTree T);
int main(void)
{
BiTree T;
CreateBiTree(&T);
PreOrder(T);
return 0;
}
int CreateBiTree(BiTree *T)
{
char data;
scanf("%c",&data);
if(data=='#')
{
*T==NULL;
}
else
{
*T=(BiTree)malloc(sizeof(BiTNode));
(*T)->data=data;
CreateBiTree(&(*T)->lchild);
CreateBiTree(&(*T)->rchild);
}
return 0;
}
void Visit(BiTree T)
{
printf("%c",T);
}
void PreOrder(BiTree T)
{
if(T!=NULL)
{
Visit(T);
PreOrder(T->lchild);
PreOrder(T->rchild);
}
}

Answer 1

In your Code you have many issues :-
In CreateBiTree(BiTree *T) function, you only modified single pointer for root, rchild and lchild. you should define Bitree *T locally in this function.
what is *T==NULL? Are you initializing or comparing?
scanf("%c",&data); this statement will also create a problem in character case. this statement will wait for '\n' also. so you should write scanf(" %c",&data).
*T=(BiTree)malloc(sizeof(BiTNode)); this statement is also wrong, malloc return pointer, so you should do correct type casting. *T=(BiTree *)malloc(sizeof(BiTNode));
i have modified you source code for your reference, have look
//it can work
#include<stdio.h>
#include<stdlib.h>
using namespace std;
typedef struct BiTNode
{
char data;
struct BiTNode* rchild;
struct BiTNode* lchild;
}BiTNode;
typedef BiTNode BiTree;
BiTree *CreateBiTree();
void Visit(BiTree **T);
void PreOrder(BiTree *T);
void InOrder(BiTree T);
void PostOrder(BiTree T);
int main(void)
{
BiTree *T;
T=CreateBiTree();
PreOrder(T);
return 0;
}
BiTree *CreateBiTree()
{
BiTree *T;
char data;
scanf(" %c",&data);
printf("............%c\n",data);
if(data=='#')
return NULL;
T=(BiTree *)malloc(sizeof(BiTree));
T->data=data;
printf("Enter left child of %c:\n",data);
T->lchild=CreateBiTree();
printf("Enter right child of %c:\n",data);
T->rchild=CreateBiTree();
return T;
}
void Visit(BiTree **T)
{
printf("%c",(*T)->data);
}
void PreOrder(BiTree *T)
{
if(T!=NULL)
{
Visit(&T);
PreOrder(T->lchild);
PreOrder(T->rchild);
}
}