建立二叉树及其遍历＿C语言

Question

程序无输出结果

#include<stdio.h>
#include<stdlib.h>

typedef struct ＿BiThrNod{
    int data;
    struct ＿BitThrNod *lchild,*rchild;
}BiThrNod,*BiThrTree;

void CreatBirTree(BiThrTree Tree)
{
    int el;
    scanf("%d",&el);
    if(el == 0) Tree = NULL;
    else
    {
        Tree = (BiThrTree)malloc(sizeof(BiThrNod));
        Tree -> data = el;
        printf("%d \n",Tree->data);
        CreatBirTree(Tree-> lchild);
        CreatBirTree(Tree-> rchild);
    }
}

void PreOrder(BiThrTree Tree)
{
    if(Tree)
    {
        printf("%d ",Tree->data);
        PreOrder(Tree->lchild);
        PreOrder(Tree->rchild);
    }
}

int main()
{
    BiThrTree T;
    CreatBirTree(T);
    PreOrder(T);
    return 0;
}

Answer 1

创建二叉树的时候错了 要传入树的指针的指针才能创建成功, 才能更改指针
main 函数这句也改下 CreatBirTree(T); -》 CreatBirTree(&T);
有一个参考

void CreatBirTree(BiThrTree *Tree)
{
    int el;
    scanf("%d",&el);
    if(el == 0) *Tree = NULL;
    else
    {
        *Tree = (BiThrTree)malloc(sizeof(BiThrNod));
        (*Tree)-> data = el;
        printf("%d \n",(*Tree)->data);
        CreatBirTree(&(*Tree)->lchild);
        CreatBirTree(&(*Tree)->rchild);
    }
}