树的创建

1.代码

#include<iostream>
#define Maxsize 10000
using namespace std;
typedef char ElemType;
typedef struct node
{
	ElemType data;
	struct node *lchild;
	struct node *rchild;
}BTNode;
void CreateBtree(BTNode *&b,char *str);//创建二叉树 
void PreOrder(BTNode *b);//先序遍历输出二叉树
void InOrder(BTNode *b);//中序遍历输出二叉树 
void PostOrder(BTNode *b);//后序遍历输出二叉树
void DestroyBtree(BTNode *&b);//销毁二叉树 
int main()
{
	BTNode *b;
	char str[Maxsize];
	cin>>str;
	CreateBtree(b,str);
	cout<<"先序遍历:";
	PreOrder(b);
	cout<<endl;
	cout<<"中序遍历:";
	InOrder(b);
	cout<<endl;
	cout<<"后序遍历:";
	PostOrder(b);
	DestroyBtree(b);
	return 0; 
}
void CreateBtree(BTNode *&b,char *str)//创建二叉树 
{
	BTNode *St[Maxsize],*p;
	int k,j=0,top=-1;
	char ch;
	b=NULL;
	ch=str[j];
	while(ch!='\0')
	{
		switch(ch)
		{
			case '(':top++;St[top]=p;k=1;break;
			case ')':top--;break;
			case ',':k=2;break;
			default:p=new BTNode;
			p->data=ch;
			p->lchild=p->rchild=NULL;
			if(b==NULL)
			   b=p;
			else
			{
				switch(k)
				{
					case 1:St[top]->lchild=p;break;
					case 2:St[top]->rchild=p;break;
				 } 
			}
		}
		j++;
		ch=str[j];
	}
 } 
 void PreOrder(BTNode *b)//先序遍历输出二叉树
 {
 	if(b!=NULL)
 	{
 		cout<<b->data;
 		PreOrder(b->lchild);
 		PreOrder(b->rchild);
	 }
 }
void InOrder(BTNode *b)//中序遍历输出二叉树 
{
	if(b!=NULL)
 	{
 		InOrder(b->lchild);
 		cout<<b->data;
 		InOrder(b->rchild);
	 }
 } 
 void PostOrder(BTNode *b)//后序遍历输出二叉树
 {
 	if(b!=NULL)
 	{
 		PostOrder(b->lchild);
 		PostOrder(b->rchild);
 		cout<<b->data;
	 }
 }
 void DestroyBtree(BTNode *&b)//销毁二叉树 
 {
 	if(b!=NULL)
 	{
 	 DestroyBtree(b->lchild);
 	 DestroyBtree(b->rchild);
 	 delete(b);
	 }
 }

2.运行结果截图