#ifndef BITREE_H
#define BITREE_H

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

typedef char ElementType;
typedef struct treenode
{
    ElementType data;
    struct treenode *leftchild;
    struct treenode *rightchild;
} TreeNode;

/*使用先序遍历创建二叉树*/
void create_bitree(TreeNode *T)
{
    ElementType ch;

    scanf(" %c",&ch);
    if(ch!='#')
    {
        T=(TreeNode*)malloc(sizeof(TreeNode));
        T->data=ch;
        create_bitree(T->leftchild);
        create_bitree(T->rightchild);
    }
    else
    {
        T=NULL;
    }
}


/*先序遍历*/
void pre_order_traversal(TreeNode *T)
{
    ElementType data;
    if(T!=NULL)
    {
        data=T->data;
        printf("%d ",data);
        pre_order_traversal(T->leftchild);
        pre_order_traversal(T->rightchild);
    }
}

#endif

#include<stdio.h>
#include"BiTree.h"

int main()
{
    TreeNode *T;
    T=NULL;

    printf("type the binary tree with previous order:");
    create_bitree(T);
    pre_order_traversal(T);

    return 0;
}