补充一下代码

typedef int myType;

typedef struct treeNode 
{
    myType element;     //值域元素
    struct treeNode *lchild;    //左孩子
    struct treeNode *rchild;    //右孩子
}Btree;

void createTree(Btree **T)  //传入一个Btree的指针的地址
{
    myType data;
    scanf("%d", &data);

    if(data == -1) {    //-1代表终端节点值
        *T = NULL;
    } else {
        *T = (Btree *)malloc(sizeof(struct treeNode));  
        (*T)->element = data;
        printf("请输入%d的左孩子节点：", data);
        createTree(&((*T)->lchild));
        printf("请输入%d的右孩子节点：", data);
        createTree(&((*T)->rchild));
    }
}

void preOrder(Btree *T)
{
    if(T != NULL) {
        printf("%d ", T->element);  //访问根节点
        preOrder(T->lchild);    //先根序遍历左子树
        preOrder(T->rchild);    //先根序遍历右子树
    }
} 

void inOrder(Btree *T)
{
    if(T != NULL) {
        inOrder(T->lchild);     //中根序遍历左子树
        printf("%d ", T->element);  //访问根节点 
        inOrder(T->rchild); //中根序遍历右子树
    }
}

void postOrder(Btree *T)
{
    if(T != NULL) {
        postOrder(T->lchild);   //后根序遍历左子树
        postOrder(T->rchild);   //后根序遍历右子树
        printf("%d ", T->element);  //访问根节点
    }
}

void distroyTree(Btree **T)
{
    Btree *pl, *pr;
    if((*T) == NULL) {
        return ;
    } else {
        pl = (*T)->lchild;  //保存左孩子的地址
        pr = (*T)->rchild;  //保存右孩子的地址
        (*T)->lchild = NULL;
        (*T)->rchild = NULL;
        free(*T);   //释放根节点
        (*T) = NULL;
        distroyTree(&pl);   //递归销毁
        distroyTree(&pr);
    }
}

int tree_deep(Btree *T)
{
    int deep = 0;
    if(T) {
        int leftdeep = tree_deep(T->lchild);    
        int rightdeep = tree_deep(T->rchild);
        deep = leftdeep > rightdeep ? leftdeep+1 : rightdeep+1;
    }

    return deep;
}