递归实现二叉树基本操作

源代码实现：

#include<iostream>
using namespace std;
typedef struct node{
	struct node * lchild;
	struct node * rchild;
	char data;
}BiTreeNode,*BiTree;

void CreateBiTree(BiTree &T){
	char c;
	cin>>c;
	if('#'==c)
		T = NULL; 
	 else
	 {
	 	T = new BiTreeNode;
	 	T->data = c;
	 	CreateBiTree(T->lchild);
	 	CreateBiTree(T->rchild);
	  } 
		
}

void PreOrderTraverse(BiTree T)
{
	if(T)
	{
		cout<<T->data;
		PreOrderTraverse(T->lchild);
		PreOrderTraverse(T->rchild);
	}
}

void InOrderTravers(BiTree T){
	if(T){
	InOrderTravers(T->lchild);
	cout<<T->data;
	InOrderTravers(T->rchild);
	}	
}

void PostOrderTravers(BiTree T){
	if(T){
	PostOrderTravers(T->lchild);
	PostOrderTravers(T->rchild);
	cout<<T->data;
	}	
}

void Copy(BiTree T,BiTree &NewT)
{
	if(T==NULL)
	{
		NewT=NULL;
		return;
	}
	else{
	NewT=new BiTreeNode;
	NewT-> data=T-> data;
	Copy(T->lchild,NewT->lchild);
	Copy(T->rchild,NewT->rchild);
	}
}

int Depth(BiTree T)
{
	int m,n;
	if(T==NULL)  return 0;
	else {
		m=Depth(T->lchild);
		n=Depth(T->rchild);
		if(m>n) return (m+1);
		else return (n+1);
	}
}

int NodeCount(BiTree T)
{
	if(T==NULL) return 0;
	else return NodeCount(T->lchild)+NodeCount(T->rchild)+1;
}

int main(){
	BiTree T;
	BiTree NewT;
	cout<<"创建二叉树:\n";
	CreateBiTree(T);
	cout<<"***  ***  ***  ***  ***\n";
	cout<<"请选择：\n";
	cout<<"1.先序遍历二叉树 \n";
	cout<<"2.中序遍历二叉树 \n";
	cout<<"3.后序遍历二叉树 \n";
	cout<<"4.复制二叉树 \n";
	cout<<"5.计算二叉树的深度 \n";
	cout<<"6.统计二叉树中结点的个数 \n";
	cout<<"***  ***  ***  ***  ***\n";
	int a;
	cin>>a;
	cout<<endl;
	switch(a)
	{
		case 1:PreOrderTraverse(T);break;
		case 2:InOrderTravers(T);break;
		case 3:PostOrderTravers(T);break;
		case 4:Copy(T,NewT);break;
		case 5:cout<<Depth(T);break;
		case 6:cout<<NodeCount(T);break;
		default:cout<<"ERROR!"<<endl;
	}
	return 0;
	
}