数据结构与算法之二叉链树

数据结构
李春葆系列

#include<iostream>
#include<stdio.h>
#include<stdlib.h>
#include<algorithm>
#define MaxSize  100
using namespace std;
typedef  char ElemType ;
typedef struct node
{
	ElemType data;
	struct node * lchild;
	struct node * rchild;
}BTNode;
void CreateBTree(BTNode *&b,char *str)// 创造二叉树 
{
	BTNode *St[MaxSize],*p;
	int top=-1,k,j=0;
	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=(BTNode *)malloc(sizeof(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 DestroyBTree(BTNode *& b)//销毁二叉树 
{
	if(b!=NULL)
	{
		DestroyBTree(b->lchild);
		DestroyBTree(b->rchild);
		free(b);
	}
 } 
 
BTNode *FindNode(BTNode * b,ElemType x)//查找结点 
{
	BTNode *p;
	if(b==NULL)
	{
		return NULL;
	}
	else if(b->data==x)
	{
		return b;
	}
	else
	{
		p=FindNode(b->lchild,x);
		if(p!=NULL)
		{
			return p;
		}
		else
		{
			return FindNode(b->rchild,x);
		}
	}
}
BTNode *LchildNode(BTNode *p)//返回结点p的左孩子结点 
{
	return p->lchild;
 } 
 
 
 BTNode *RchildNode(BTNode *p)//返回结点p的右孩子结点 
 {
 	return p->rchild;
 }
 
int BTHeight(BTNode *b)//求高度 
 {
 	if(b==NULL)
 	{
 		return (0);
	 }
	 else
	 {
	 	return (BTHeight(b->lchild)>BTHeight(b->rchild))?(BTHeight(b->lchild)+1):(BTHeight(b->rchild)+1);
	 }
 }
 
void DispBTree(BTNode *b)//输出二叉树 
{
	if(b!=NULL)
	{
		printf("%c",b->data);
		if(b->lchild!=NULL||b->rchild!=NULL)
		{
			printf("(");
			DispBTree(b->lchild);
			if(b->rchild!=NULL)
			{
				printf(",");
			}
			DispBTree(b->rchild);
			printf(")");
			
		}
	}
}

int main()
{   BTNode *b,*p;
	CreateBTree(b,"A(B(D,E(H(J,K(L,M(,N))))),C(F,G(,I)))");
	DispBTree(b);
	p = FindNode(b, 'H');
    if(p != NULL)
    {       printf("\n");
            printf("左孩子为%c\n", LchildNode(p)->data);
            printf("右孩子为%c\n",RchildNode(p)->data);
    }
    else
    {
 	   printf("这是一个叶子结点，无孩子\n"); 
	}
    printf("树高:%d\n",BTHeight(b));
    DestroyBTree(b);
    printf("二叉树已经释放"); 
}