#include<stdio.h>
#include<malloc.h>
#include<stdlib.h>
typedef char DataType;
typedef struct BitNode
{DataType data;
struct BitNode *lchild,*rchild;
}BitNode,*BitTree;
void BinTreeInit(BitTree *BT)    /*初始化二叉树树根指针置空*/
{
    BT=NULL;
}
void BinTreeCreat(BitTree BT)/*按先序建立一个二叉树*/
{   
    char ch;
    scanf(&ch);
    if(ch==' ')   BT=NULL;
    else{
        BT=((BitNode *)malloc(sizeof(BitNode)));
        BT->data=ch;
        BinTreeCreat(BT->lchild);
        BinTreeCreat(BT->rchild);
    }
}
int BinTreeEmpty(BitTree BT)/*检查二叉树是否为空*/
{
    if(BT==NULL)
    printf("是空二叉树");
    else
    printf("不是二叉树");
}
void BinTraverse(BitTree BT) /先序遍历二叉树*/
{
    if(BT!=NULL)
    {
        printf("%d",BT->data);
        BinTraverse(BT->lchild);
        BinTraverse(BT->rchild);
    }

}

int BinTreeDepth(BitTree BT) /*求二叉树的深度*/
{
    int i;
    if(BT)
    {
        int dethl=BinTreeDepth(BT->lchild);
        int dethr=BinTreeDepth(BT->rchild);
        i=1+(dethl>dethr?dethl:dethr);
    }
    else i=0;
    return i;
}
int BinTreeCount(BitTree BT)/*求二叉树中所有结点数*/
{
    int node;
    if(BT)
    {
        int m=BinTreeCount(BT->lchild);
        int n=BinTreeCount(BT->rchild);
        node=m+n+1;
    }
    else
        node=0;
    return node;
}
void BinTreeClear(BitTree BT)/*清除二叉树变为空树*/
{
    if(BT!=NULL)
    {
      BT->lchild=NULL;
      BT->rchild=NULL;
      BT=NULL;
    }
}

int main()
{   
    BitTree *BT;
    void BinTreeCreat(BitTree BT);
    void BinTreeInit(BitTree *BT);
    int BinTreeEmpty(BitTree BT);
    void BinTraverse1(BitTree BT);
    int BinTreeDepth(BitTree BT);
    int BinTreeCount(BitTree BT);
    void BinTreeClear(BitTree BT);
    return 0;
}