[导入]AVL Tree的一个简单实现
#ifndef _ALV_TREE_H
#define _ALV_TREE_H
#define Max(a,b) (((a)>(b))?(a):(b))
#include <iostream>
template<class T>
class AVLTree
{
struct _TreeNode;
typedef struct _TreeNode TreeNode;
struct _TreeNode
{
T data;
int height;
TreeNode* left;
TreeNode* right;
};
private:
TreeNode *root;
public:
AVLTree()
{
this->root=NULL;
}
~AVLTree()
{
this->MakeEmpty(this->root);
}
int GeiHeight()
{
return this->GetHeightUtil(this->root);
}
void Insert(T data)
{
this->root=this->InsertUtil(this->root,data);
}
void Delete(T data)
{
this->root=this->DeleteUtil(this->root,data);
}
void Print()
{
/*if(root!=NULL)
{
std::cout<<"The root node is: "<<root->data<<std::endl;
}*/
for(int level=0;;level++)
{
if(this->PrintUtil(this->root,level)==0)
{
break;
}
std::cout<<std::endl;
}
}
private:
TreeNode *InsertUtil(TreeNode *_root,T data)
{
if(_root==NULL)
{
_root=new TreeNode();
_root->data=data;
_root->left=0;
_root->right=0;
_root->height=0;
}
if(data>_root->data)
{
_root->right=this->InsertUtil(_root->right,data);
if(GetHeightUtil(_root->right)-GetHeightUtil(_root->left)==2)
{
if(data>_root->right->data)
{
_root=this->SingleRotateWithRight(_root);
}
else
{
_root=this->DoubleRotateWithRight(_root);
}
}
}
else if(data<_root->data)
{
_root->left=this->InsertUtil(_root->left,data);
if(GetHeightUtil(_root->left)-GetHeightUtil(_root->right)==2)
{
if(data<_root->left->data)
{
_root=this->SingleRotateWithLeft(_root);
}
else
{
_root=this->DoubleRotateWithLeft(_root);
}
}
}
_root->height=Max(GetHeightUtil(_root->left),GetHeightUtil(_root->right))+1;
return _root;
}
TreeNode *DeleteUtil(TreeNode *_root,T data)
{
if(_root==NULL)
{
return _root;
}
else if(_root->data==data
&&_root->left==NULL
&&_root->right==NULL)
{
delete _root;
return NULL;
}
else if(_root->data==data
&&_root->left!=NULL
&&_root->right==NULL)
{
TreeNode* tmpNode=_root->left;
delete _root;
tmpNode->height=this->RecalculateHeight(tmpNode);
return tmpNode;
}
else if(_root->data==data
&&_root->left==NULL
&&_root->right!=NULL)
{
TreeNode *tmpNode=_root->right;
delete _root;
tmpNode->height=this->RecalculateHeight(tmpNode);
return tmpNode;
}
else
{
if(data==_root->data)
{
TreeNode *tmpNode,*parentNode;
tmpNode=_root->right->right;
parentNode=_root->right;
if(tmpNode!=NULL)
{
while(tmpNode->right!=NULL)
{
parentNode->height-=1;
parentNode=tmpNode;
tmpNode=tmpNode->right;
}
parentNode->right=NULL;
_root->data=tmpNode->data;
delete tmpNode;
}
else
{
_root=parentNode;
}
_root->height=this->RecalculateHeight(_root);
//TreeNode *tmpNode=this->FindMax(_root->right);
//_root->data=tmpNode->data;
if(GetHeightUtil(_root->left)-GetHeightUtil(_root->right)==2)
{
if(_root->left->left!=NULL)
{
_root=this->SingleRotateWithLeft(_root);
}
else if(_root->left->right!=NULL)
{
_root=this->DoubleRotateWithLeft(_root);
}
}
}
else
if(data>_root->data)
{
_root->right=this->DeleteUtil(_root->right,data);
_root->height=this->RecalculateHeight(_root);
if(GetHeightUtil(_root->left)-GetHeightUtil(_root->right)==2)
{
if(_root->left->left!=NULL)
{
_root=this->SingleRotateWithLeft(_root);
}
else if(_root->left->right!=NULL)
{
_root=this->DoubleRotateWithLeft(_root);
}
}
}
else
{
_root->left=this->DeleteUtil(_root->left,data);
_root->height=this->RecalculateHeight(_root);
if(GetHeightUtil(_root->right)-GetHeightUtil(_root->left)==2)
{
if(_root->right->right!=NULL)
{
_root=this->SingleRotateWithRight(_root);
}
else if(_root->right->left!=NULL)
{
_root=this->DoubleRotateWithRight(_root);
}
}
}
}
//_root->height=this->RecalculateHeight(_root);
return _root;
}
void MakeEmpty(TreeNode *_root)
{
if(_root==NULL)
{
return;
}
else
{
MakeEmpty(_root->left);
MakeEmpty(_root->right);
delete _root;
}
}
int GetHeightUtil(TreeNode *_root)
{
/*if(_root==NULL|| (_root->left==NULL && _root->right==NULL))
{
return 0;
}
else
{
return 1+GetHeightUtil(_root->left)+GetHeightUtil(_root->right);
}*/
if(_root==NULL)
{
return -1;
}
else
{
return _root->height;
}
}
int PrintUtil(TreeNode *node, int level)
{
if(node==NULL||level<0)
{
return 0;
}
else
{
if(level==0)
{
std::cout<<node->data<<" ";
return 1;
}
return PrintUtil(node->left,level-1)+PrintUtil(node->right,level-1);
}
}
TreeNode *SingleRotateWithLeft(TreeNode *node)
{
TreeNode *tmpNode=node->left;
node->left=tmpNode->right;
tmpNode->right=node;
node->height=Max(GetHeightUtil(node->left),GetHeightUtil(node->right))+1;
tmpNode->height=Max(GetHeightUtil(tmpNode->left),GetHeightUtil(tmpNode->right))+1;
return tmpNode;
}
TreeNode*SingleRotateWithRight(TreeNode *node)
{
TreeNode *tmpNode=node->right;
node->right=tmpNode->left;
tmpNode->left=node;
node->height=Max(GetHeightUtil(node->left),GetHeightUtil(node->right))+1;
tmpNode->height=Max(GetHeightUtil(tmpNode->left),GetHeightUtil(tmpNode->right))+1;
return tmpNode;
}
TreeNode* DoubleRotateWithLeft(TreeNode *node)
{
node->left=this->SingleRotateWithRight(node->left);
return this->SingleRotateWithLeft(node);
}
TreeNode* DoubleRotateWithRight(TreeNode *node)
{
node->right=this->SingleRotateWithLeft(node->right);
return this->SingleRotateWithRight(node);
}
TreeNode* FindMax(TreeNode *node)
{
//T maxData;
while(node!=NULL&&node->right!=NULL)
{
node=node->right;
}
//maxData=node->data;
return node;
}
int RecalculateHeight(TreeNode *node)
{
if(node==NULL)
{
return -1;
}
else
{
node->height=Max(RecalculateHeight(node->left),RecalculateHeight(node->right))+1;
return node->height;
}
}
};
#endif
文章来源: http://www.cppblog.com/dingding/archive/2008/09/28/62997.html