2024.2.7

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
typedef char datatype;
//结构体
typedef struct node
{
	datatype data;
    struct node *lchild;
	struct node *rchild;
}*Btree;
//创建结点
Btree creat()
{
	Btree s=(Btree)malloc(sizeof(struct node));
	if(s==NULL) return NULL;
	s->data='\0';
	s->lchild=s->rchild=NULL;
	return s;
}
//创建树
Btree creat_tree()
{
	datatype element;
	printf("please input element:");
	scanf(" %c",&element);
	if(element=='#')
		return NULL;
	Btree tree=creat();
	tree->data=element;
	tree->lchild=creat_tree();
	tree->rchild=creat_tree();
	return tree;
}
//先序遍历
void first(Btree tree)
{
	if(tree==NULL) return;
	printf("%c",tree->data);
	first(tree->lchild);
	first(tree->rchild);
}
//中序遍历
void mid(Btree tree)
{
	if(tree==NULL) return;
	mid(tree->lchild);
	printf("%c",tree->data);
	mid(tree->rchild);
}
	//后序遍历
void last(Btree tree)
{
	if(tree==NULL) return;
	last(tree->lchild);
	last(tree->rchild);
	printf("%c",tree->data);
}
//结点个数
void count(Btree tree,int *n0,int *n1,int *n2)
{
	if(tree==NULL)
		return;
	if(tree->lchild ==NULL&&tree->rchild==NULL)
		++*n0;
	else if(tree->lchild&&tree->rchild)
		++*n2;
	else
		++*n1;
	count(tree->lchild,n0,n1,n2);
	count(tree->rchild,n0,n1,n2);
}
//计算深度
int high(Btree tree)
{
	if(tree==NULL)
		return 0;
	int left=1+high(tree->lchild);
	int right=1+high(tree->rchild);
	return left>right?left:right;
}
int main(int argc, const char *argv[])
{
  Btree tree=creat_tree();
  printf("first:");
  first(tree);
  puts("");
  printf("mid:");
  mid(tree);
  puts("");
  printf("last:");
  last(tree);
  puts("");
  int n0=0,n1=0,n2=0;
  count(tree,&n0,&n1,&n2);
  printf("n0=%d n1=%d n2=%d n=%d\n",n0,n1,n2,n0+n1+n2);
  int high_tree=high(tree);
  printf("high_tree=%d\n",high_tree);
  return 0;
}