二叉树

#include <iostream>
#include "malloc.h"
using namespace std;

typedef struct BTNode
{
 char data;
 struct BTNode *Lchild,*Rchild;
}BTNode;

struct BTNode *lpRoot,*temp;
void visit(char a)
{
 printf("%c ",a);
}
//先序遍历的递归算法
void PreorderTraverse(BTNode *T)
{
 if (T!=NULL)
 {
  cout<<T->data;
  PreorderTraverse(T->Lchild);
  PreorderTraverse(T->Rchild);
 }
}

//中序遍历的递归算法
void InorderTraverse(BTNode *T)
{
 if (T!=NULL)
 {
  InorderTraverse(T->Lchild);
  visit(T->data);
  InorderTraverse(T->Rchild);
 }
}

//后序遍历的递归算法
void PostorderTraverse(BTNode *T)
{
 if (T!=NULL)
 {
  PostorderTraverse(T->Lchild);
  PostorderTraverse(T->Rchild);
  visit(T->data);
 }
}

BTNode *Preorder_Create_BTree(BTNode *T)
{
 char ch;
 cin>>ch;
 if (ch=='0')
 {
  T=NULL;
  return(T);
 }
 else
 {
  T=(BTNode*)malloc(sizeof(BTNode));
  T->data=ch;
  Preorder_Create_BTree(T->Lchild);
  Preorder_Create_BTree(T->Rchild);
  return(T);
 }
}

void Release(BTNode *T)
{
 if (T!=NULL)
 {
  Release(T->Lchild);
  Release(T->Rchild);
  delete T;
  T=NULL;
 }
}
void main()
{
 temp=Preorder_Create_BTree(lpRoot);

 PreorderTraverse(temp);
 getchar();
}