二叉排序树

#include <iostream>
using namespace std;
struct BinaryTreeNode
{
int data;
BinaryTreeNode *lchild,*rchild;
};
class BinarySearchTree
{
private:
BinaryTreeNode *root;
public:
BinarySearchTree():root(NULL) {}           //构造函数
void Insert(BinaryTreeNode *&t,int key);   //插入元素
void PreOrder(BinaryTreeNode *t);          //前序遍历
void InOrder(BinaryTreeNode *t);           //中序遍历
void PostOrder(BinaryTreeNode *t);         //后序遍历
bool Search(BinaryTreeNode *t,int key);    //搜索元素
BinaryTreeNode *GetRoot() { return root;}  //获取根节点
void DelNode(BinaryTreeNode *&t,int key);  //删除key元素
void Del(BinaryTreeNode *&t);              //删除
};

void BinarySearchTree::Insert(BinaryTreeNode *&t,int key)
{
if(!t)
{
BinaryTreeNode *NewNode=new BinaryTreeNode;
NewNode->data=key;
NewNode->rchild=NewNode->lchild=NULL;
t=NewNode;
return;
}
BinaryTreeNode *p,*prev=0;
p=t;
while(p)
{
prev=p;
if(key<p->data) p=p->lchild;
else if(key==p->data) { cout<<"树中已有该节点!"<<endl; return ;}
else if(key>p->data) p=p->rchild;
}
if(key<prev->data)
{
BinaryTreeNode *NewNode=new BinaryTreeNode;
NewNode->data=key;
NewNode->rchild=NewNode->lchild=NULL;
prev->lchild=NewNode;
}
else if(key>prev->data)
{
BinaryTreeNode *NewNode=new BinaryTreeNode;
NewNode->data=key;
NewNode->rchild=NewNode->lchild=NULL;
prev->rchild=NewNode;
}
}

void BinarySearchTree::PreOrder(BinaryTreeNode *t)
{
if(t)
{
cout<<t->data<<" ";
PreOrder(t->lchild);
PreOrder(t->rchild);
}
}

void BinarySearchTree::InOrder(BinaryTreeNode *t)
{
if(t)
{
InOrder(t->lchild);
cout<<t->data<<" ";
InOrder(t->rchild);
}
}

void BinarySearchTree::PostOrder(BinaryTreeNode *t)
{
if(t)
{
PostOrder(t->lchild);
PostOrder(t->rchild);
cout<<t->data<<" ";
}
}
bool BinarySearchTree::Search(BinaryTreeNode *t,int key)
{
if(!t)
{
cout<<"Not find!"<<endl;
return false;
}
else if(key<t->data) return Search(t->lchild,key);
else if(key>t->data) return Search(t->rchild,key);
else if(key==t->data) { cout<<"Has been found!"<<endl; return true;}
}

void BinarySearchTree::Del(BinaryTreeNode *&t)
{
BinaryTreeNode *del=NULL,*p=NULL;
if(!t->rchild)         //如果右子树为空
{
del=t;
t=t->lchild;
delete del;
}
else if(!t->lchild)         //如果左子树为空
{
del=t;
t=t->rchild;
delete del;
}
else if(t->lchild&&t->rchild)        //存在左右子女
{
p=t;
del=t->lchild;
while(!del->rchild)
{
p=del;
del=del->rchild;
}
t->data=del->data;
if(p!=t)
p->rchild=del->lchild;
else
p->lchild=del->lchild;
delete del;
}
}

void BinarySearchTree::DelNode(BinaryTreeNode *&t,int key)
{
if(!t)  return ;
if(key==t->data) Del(t);
else if(key<t->data) DelNode(t->lchild,key);
else if(key>t->data) DelNode(t->rchild,key);
}
int main()
{
BinarySearchTree b;
BinaryTreeNode *root=NULL;
int a[10]={4,66,3,77,-4,7,88,56,93,0};
cout<<"二叉搜索树测试"<<endl;
for(int i=0;i<10;++i)
b.Insert(root,a[i]);
cout<<"前序遍历"<<endl;
b.PreOrder(root);
cout<<endl;
cout<<"中序遍历"<<endl;
b.InOrder(root);
cout<<endl;
cout<<"后序遍历"<<endl;
b.PostOrder(root);
cout<<endl;
cout<<"搜索测试,搜索0"<<endl;
b.Search(root,0);
cout<<"搜索测试，搜索13"<<endl;
b.Search(root,13);
cout<<"删除测试,删除93"<<endl;
b.DelNode(root,93);
cout<<"已删除93"<<endl;
cout<<"删除后结果"<<endl;
b.InOrder(root);
cout<<"插入测试"<<endl;
cout<<"插入6后！"<<endl;
b.Insert(root,6);
b.InOrder(root);
system("pause");
return 0;
}