Size Balanced Tree是OI神犇陈启峰发明的,据说是目前最高效的二叉查找树,搞了好长时间终于弄出来了~这个版本的SBT本来是打算用来实现STL的set的,所以树中不存在两个键值一样的元素,当然改成multiset那样的也不是很麻烦~原本按自己的理解想设计自底向上调整的SBT,结果最后发现这样的SBT有很大的问题最简单的例子就是如果插入的数据是单调有序的,那么显然这棵SBT就会严重倾向一侧,所以必须是自顶向下调整~这次写SBT模板收获很大^_^~大家要是发现bug请留言哈~
被虐。。。重写+debug。。。
// =============================================================================
//
// Filename: size_balanced_tree.h
//
// Description: Size Balanced Tree
//
// Version: 1.1
// Created: 03/29/2012 01:00:29 PM
// Revision: none
// Compiler: g++
//
// Author: SphinX (Whisper), [email protected]
// Company: HFUT
//
// =============================================================================
#ifndef SIZE_BALANCED_TREE
#define SIZE_BALANCED_TREE
#include
#include
#include "dsexceptions.h"
using std::cout;
using std::endl;
template
class SizeBalancedTree
{
private:
struct SizeBalancedNode
{
T element;
SizeBalancedNode * left;
SizeBalancedNode * right;
int node_size;
SizeBalancedNode(const T & _element,
SizeBalancedNode * lt, SizeBalancedNode * rt, int sz = 1)
: element(_element), left(lt), right(rt), node_size(sz) {}
};
public:
SizeBalancedTree()
{
root = NULL;
tree_size = 0;
}
SizeBalancedTree(SizeBalancedTree & rhs)
{
this->root = clone(rhs.root);
this->tree_size = rhs.size();
}
~SizeBalancedTree()
{
clear();
}
const SizeBalancedTree & operator = (const SizeBalancedTree & rhs)
{
if (this != &rhs)
{
this->clear();
this->root = clone(rhs.root);
this->tree_size = rhs.tree_size;
}
return (*this);
}
int size() const
{
return tree_size;
}
bool empty() const
{
return size() == 0;
}
bool contains(const T & x) const
{
return contains(x, root);
}
const T & findMin() const
{
if (empty())
{
throw UnderflowException();
}
return findMin(root)->element;
}
const T & findMax() const
{
if (empty())
{
throw UnderflowException();
}
return findMax(root)->element;
}
int rank(const T & x) const
{
if (!contains(x))
{
return -1;
}
return rank(x, root);
}
const T & select(int _rank) const
{
if (_rank < 0)
{
throw UnderflowException();
}
if (_rank >= size())
{
throw OverflowException();
}
return select(_rank, root)->element;
}
void showTree() const
{
showTree(root);
return ;
}
void clear()
{
clear(root);
tree_size = 0;
return ;
}
void insert(const T & x)
{
if (contains(x))
{
return ;
}
++tree_size;
insert(x, root);
return ;
}
void remove(const T & x)
{
if (!contains(x))
{
return ;
}
--tree_size;
remove(x, root);
return ;
}
private:
SizeBalancedNode * root;
int tree_size;
int getNodeSize(SizeBalancedNode * t) const
{
if (NULL == t)
{
return 0;
}
return t->node_size;
}
bool contains(const T & x, SizeBalancedNode * t) const
{
while (t != NULL)
{
if (x < t->element)
{
t = t->left;
}
else if (t->element < x)
{
t = t->right;
}
else
{
return true;
}
}
return false;
}
SizeBalancedNode * clone(SizeBalancedNode * t) const
{
if (NULL == t)
{
return NULL;
}
return new SizeBalancedNode(t->element,
clone(t->left), clone(t->right));
}
SizeBalancedNode * findMin(SizeBalancedNode * t) const
{
if (t != NULL)
{
while (t->left != NULL)
{
t = t->left;
}
}
return t;
}
SizeBalancedNode * findMax(SizeBalancedNode * t) const
{
if (t != NULL)
{
while (t->right != NULL)
{
t = t->right;
}
}
return t;
}
int rank(const T & x, SizeBalancedNode * t) const
{
int _rank = 0;
while (t != NULL)
{
if (x < t->element)
{
t = t->left;
}
else if (t->element < x)
{
_rank += getNodeSize(t->left) + 1;
t = t->right;
}
else
{
_rank += getNodeSize(t->left);
break ;
}
}
return _rank;
}
SizeBalancedNode * select(int _rank, SizeBalancedNode * t) const
{
while (t != NULL)
{
if (_rank < getNodeSize(t->left))
{
t = t->left;
}
else if (getNodeSize(t->left) < _rank)
{
_rank -= getNodeSize(t->left) + 1;
t = t->right;
}
else
{
break ;
}
}
return t;
}
void showTree(SizeBalancedNode * t) const
{
if (t != NULL)
{
cout << "The element of this Node is " << t->element << endl;
if (t->left != NULL)
{
cout << "Walk into left child!" << endl;
showTree(t->left);
cout << "Walk back!" << endl;
}
cout << "The element of this Node is " << t->element << endl;
if (t->right != NULL)
{
cout << "Walk into right child!" << endl;
showTree(t->right);
cout << "Walk back!" << endl;
}
}
return ;
}
void clear(SizeBalancedNode * & t)
{
if (t != NULL)
{
clear(t->left);
clear(t->right);
delete t;
t = NULL;
}
return ;
}
void rotateWithLeft(SizeBalancedNode * & k2)
{
SizeBalancedNode * k1 = k2->left;
k2->left = k1->right;
k1->right = k2;
k1->node_size = getNodeSize(k2);
k2->node_size = getNodeSize(k2->left) + getNodeSize(k2->right) + 1;
k2 = k1;
return ;
}
void rotateWithRight(SizeBalancedNode * & k2)
{
SizeBalancedNode * k1 = k2->right;
k2->right = k1->left;
k1->left = k2;
k1->node_size = getNodeSize(k2);
k2->node_size = getNodeSize(k2->left) + getNodeSize(k2->right) + 1;
k2 = k1;
return ;
}
void doubleWithLeft(SizeBalancedNode * & t)
{
rotateWithRight(t->left);
rotateWithLeft(t);
return ;
}
void doubleWithRight(SizeBalancedNode * & t)
{
rotateWithLeft(t->right);
rotateWithRight(t);
return ;
}
void maintain(SizeBalancedNode * & t) //Need to optimize...
{
if (t->left != NULL)
{
if (getNodeSize(t->right) < getNodeSize(t->left->left))
{
rotateWithLeft(t);
}
else if (getNodeSize(t->right) < getNodeSize(t->left->right))
{
doubleWithLeft(t);
}
}
if (t->right != NULL)
{
if (getNodeSize(t->left) < getNodeSize(t->right->right))
{
rotateWithRight(t);
}
else if (getNodeSize(t->left) < getNodeSize(t->right->left))
{
doubleWithRight(t);
}
}
if (t->left != NULL)
{
maintain(t->left);
}
if (t->right != NULL)
{
maintain(t->right);
}
return ;
}
void simpleInsert(const T & x, SizeBalancedNode * & t)
{
if (NULL == t)
{
t = new SizeBalancedNode(x, NULL, NULL);
return ;
}
++t->node_size;
if (x < t->element)
{
simpleInsert(x, t->left);
}
else if (t->element < x)
{
simpleInsert(x, t->right);
}
return ;
}
void insert(const T & x, SizeBalancedNode * & t)
{
if (NULL == t)
{
t = new SizeBalancedNode(x, NULL, NULL);
return ;
}
++t->node_size;
if (x < t->element)
{
simpleInsert(x, t->left);
}
else if (t->element < x)
{
simpleInsert(x, t->right);
}
else
{
return ;
}
maintain(t);
return ;
}
void remove(const T & x, SizeBalancedNode * & t)
{
if (NULL == t)
{
return ;
}
--t->node_size;
if (x < t->element)
{
remove(x, t->left);
}
else if (t->element < x)
{
remove(x, t->right);
}
else
{
if (t->left != NULL && t->right != NULL)
{
if (getNodeSize(t->left) < getNodeSize(t->right))
{
t->element = findMin(t->right)->element;
remove(t->element, t->right);
}
else
{
t->element = findMax(t->left)->element;
remove(t->element, t->left);
}
}
else
{
SizeBalancedNode * oldNode = t;
t = ((t->left != NULL) ? t->left : t->right);
delete oldNode;
oldNode = NULL;
}
}
return ;
}
};
/*
*template
*const typename SizeBalancedTree::SizeBalancedNode * SizeBalancedTree::nil
* = new SizeBalancedTree::SizeBalancedNode(T(), NULL, NULL, 0);
*/
#endif