C++二叉树

BiTree：

#include<iostream>
using namespace std;

struct BiTNode
{
    char data;
    BiTNode *lchild, *rchild;
}*T;
//BiTNode *T;

//先序递归创建二叉树
void CreatBiTree(BiTNode* &T)      
{
    char ch;
    if((ch=getchar()) =='#')
        T = NULL;
    else
    {
        T = new BiTNode;
        T->data = ch;
        CreatBiTree(T->lchild);
        CreatBiTree(T->rchild);
    }
}

//先序递归遍历二叉树
void PreOrderTraverse(BiTNode* &T)      
{
    if(T==NULL)
        return;
    else
    {
        cout<< T->data;
        PreOrderTraverse(T->lchild);
        PreOrderTraverse(T->rchild);
    }
}

//中序递归遍历二叉树
void InOrderTraverse(BiTNode* &T)      
{
    if(T==NULL)
        return;
    else
    {
        InOrderTraverse(T->lchild);
        cout<< T->data;
        InOrderTraverse(T->rchild);
    }
}

//后续递归遍历二叉树
void PosOrderTraverse(BiTNode* &T)     
{
    if(T==NULL)
        return;
    else
    {
        PosOrderTraverse(T->lchild);
        PosOrderTraverse(T->rchild);
        cout<< T->data;
    }
}

//清空树
void DeleteTree(BiTNode* &T)
{
    if(T!=NULL)
    {
        DeleteTree(T->lchild);
        DeleteTree(T->rchild);
        delete T;
    }
}

int main()
{
    cout<<"创建一棵树，其中A->Z字符代表树的数据，用‘#’表示空树："<<endl;
    CreatBiTree(T);

    cout<<"先序递归遍历：";
    PreOrderTraverse(T);
    cout<<endl;

    cout<<"中序递归遍历：";
    InOrderTraverse(T);
    cout<<endl;

    cout<<"后序递归遍历：";
    PosOrderTraverse(T);
    cout<<endl;

    /*cout<<"清空树后：";
    DeleteTree(T);
    cout<<"先序递归遍历：";
    PreOrderTraverse(T);
    cout<<endl;*/

    return 0;
}