二叉树遍历的递归实现

/*二叉树遍历的递归实现*/#include<stdio.h>typedef struct btnode{    char data;    struct btnode *lchild,*rchild;      /*指向左右孩子的指针*/}BinTree;/*二叉树的创建*/BinTree * CreateTree(BinTree *T){    char ch;    scanf("%c",&ch);    if(ch=='#')        return 0;    else    {        T=(BinTree *)malloc(sizeof(BinTree));        T->data=ch;        T->lchild=CreateTree(T->lchild);    /*创建左子树*/        T->rchild=CreateTree(T->rchild);    /*创建右子树*/        return(T);    }}/*先序遍历根指针为T的二叉树*/void Preorder(BinTree *T){    if(T)    {        printf("%c ",T->data);  /*访问根节点T*/        Preorder(T->lchild);    /*先序遍历左子树*/        Preorder(T->rchild);    /*先序遍历右子树*/    }}/*中序遍历根指针为T的二叉树*/void inorder(BinTree *T){    if(T)    {        inorder(T->lchild);     /*中序遍历左子树*/        printf("%c ",T->data);  /*访问根节点T*/        inorder(T->rchild);     /*中序遍历右子树*/    }}/*后序遍历根指针为T的二叉树*/void postorder(BinTree *T){    if(T)    {        postorder(T->lchild);   /*后序遍历左子树*/        postorder(T->rchild);   /*后序遍历右子树*/        printf("%c ",T->data);  /*访问根节点T*/    }}main(){    BinTree *b;    printf("请按先序的方式输入二叉树的结点元素:\n");    b=CreateTree(b);    printf("前序输出:\n");    Preorder(b);    printf("\n");    printf("中序输出:\n");    inorder(b);    printf("\n");    printf("后序输出:\n");    postorder(b);    printf("\n");}