二叉排序树之创建、查找、插入、修改

资料：二叉排序树
建议看完资料后看代码会异常清晰！！！
代码：

#include<iostream>
using namespace std;
int n,a[1010];
typedef struct node
{
	int key;
	int data;
	struct node *lchild,*rchild;
}BSTNode;//节点
void insertbst(BSTNode *&bt,int k)//插入
{
	if(bt==NULL)
	{
		bt=new node;
		bt->key=k;
		bt->lchild=bt->rchild=NULL;
	}
	else 
	{
		if(k<bt->key)insertbst(bt->lchild,k);
		else if(k>bt->key)insertbst(bt->rchild,k);
	}
}
BSTNode *find(BSTNode *&bt,int k)//查找
{
	if(bt==NULL||bt->key==k)
	{
		return bt;
	}
	else if(k<bt->key)return find(bt->lchild,k);
	else if(k>bt->key)return find(bt->rchild,k);
}
BSTNode *find1(BSTNode *&bt,int k,BSTNode *f1,BSTNode *&f)//查找要找的关键字的父亲节点
{
	if(bt==NULL)
	{
		f=NULL;
		return NULL;
	}
	else if(k==bt->key)
	{
		f=f1;
		printf("%d\n",f->key);
		return bt;
	}
	else if(k<bt->key)return find1(bt->lchild,k,bt,f);
	else if(k>bt->key)return find1(bt->rchild,k,bt,f);
	//f1用做记录f 
}
void deletep(BSTNode *&p);
void deletel(BSTNode *&p,BSTNode *&r);
void Delete(BSTNode *&bt,int k)//删除
{
	if(bt==NULL)return ;
	else if(k<bt->key)Delete(bt->lchild,k);
	else if(k>bt->key)Delete(bt->rchild,k);
	else if(k==bt->key)
	{
		deletep(bt);
	}
}
void deletep(BSTNode *&p)//分三种情况
{
	BSTNode *q;
	if(p->lchild==NULL)
	{
		q=p;
		p=p->rchild;
		delete q;
	}
	else if(p->rchild==NULL)
	{
		q=p;
		p=p->lchild;
		delete q;
	}
	else deletel(p,p->lchild);
}
void deletel(BSTNode *&p,BSTNode *&r)//删除既有左子树，有右子树的节点
{
	if(r->rchild!=NULL)
	{
		deletel(p,r->rchild);
	}
	else 
	{
		BSTNode *q;	
		p->key=r->key;
		q=r;
		r=r->lchild;
		delete q;
	}
}
void print(BSTNode *&bt)//输出排序
{
	if(bt==NULL)
	{
		return ;
	}
	print(bt->lchild);
	printf("%d ",bt->key);
	print(bt->rchild);
}
int main()
{
	//不能输入同样的数字 
	BSTNode *bt=NULL,*q,*f=NULL;
	f=new node; 
	cin>>n;
	for(int i=0;i<n;i++)
	{
		cin>>a[i];
	}
	for(int i=0;i<n;i++)
	{
		insertbst(bt,a[i]);
	}
	insertbst(bt,50);
	print(bt);
	printf("\n");
	q=find(bt,50);
	printf("%d\n",q->key);
	q=find1(bt,50,NULL,f);
	//printf("%d %d\n",q->key,f->key);
	Delete(bt,0);
	print(bt);
	printf("\n");	
	return 0;
}

标签：NULL,BSTNode,二叉,bt,else,查找,key,rchild,排序
来源： https://blog.csdn.net/weixin_46627433/article/details/110500110