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mirror of https://github.com/FWGS/xash3d-fwgs synced 2024-11-16 06:56:34 +01:00
xash3d-fwgs/vgui_support/utlrbtree.h

1290 lines
31 KiB
C++

//=========== (C) Copyright 1999 Valve, L.L.C. All rights reserved. ===========
//
// The copyright to the contents herein is the property of Valve, L.L.C.
// The contents may be used and/or copied only with the written permission of
// Valve, L.L.C., or in accordance with the terms and conditions stipulated in
// the agreement/contract under which the contents have been supplied.
//
// Purpose:
//
// $Header: $
// $NoKeywords: $
//=============================================================================
#ifndef UTLRBTREE_H
#define UTLRBTREE_H
#include "port.h"
#include "utlmemory.h"
//-----------------------------------------------------------------------------
// Tool to generate a default compare function for any type that implements
// operator<, including all simple types
//-----------------------------------------------------------------------------
template <typename T >
class CDefOps
{
public:
static bool LessFunc( const T &lhs, const T &rhs ) { return ( lhs < rhs ); }
};
#define DefLessFunc( type ) CDefOps<type>::LessFunc
//-------------------------------------
inline bool StringLessThan( const char * const &lhs, const char * const &rhs) { return ( strcmp( lhs, rhs) < 0 ); }
inline bool CaselessStringLessThan( const char * const &lhs, const char * const &rhs ) { return ( strcasecmp( lhs, rhs) < 0 ); }
//-------------------------------------
// inline these two templates to stop multiple definitions of the same code
template <> inline bool CDefOps<const char *>::LessFunc( const char * const &lhs, const char * const &rhs ) { return StringLessThan( lhs, rhs ); }
template <> inline bool CDefOps<char *>::LessFunc( char * const &lhs, char * const &rhs ) { return StringLessThan( lhs, rhs ); }
//-------------------------------------
template <typename RBTREE_T>
void SetDefLessFunc( RBTREE_T &RBTree )
{
#ifdef _WIN32
RBTree.SetLessFunc( DefLessFunc( RBTREE_T::KeyType_t ) );
#elif _LINUX
RBTree.SetLessFunc( DefLessFunc( typename RBTREE_T::KeyType_t ) );
#endif
}
//-----------------------------------------------------------------------------
// A red-black binary search tree
//-----------------------------------------------------------------------------
template <class T, class I = unsigned short>
class CUtlRBTree
{
public:
// Less func typedef
// Returns true if the first parameter is "less" than the second
typedef bool (*LessFunc_t)( T const &, T const & );
typedef T KeyType_t;
typedef T ElemType_t;
typedef I IndexType_t;
// constructor, destructor
// Left at growSize = 0, the memory will first allocate 1 element and double in size
// at each increment.
// LessFunc_t is required, but may be set after the constructor using SetLessFunc() below
CUtlRBTree( int growSize = 0, int initSize = 0, LessFunc_t lessfunc = 0 );
~CUtlRBTree( );
// gets particular elements
T& Element( I i );
T const &Element( I i ) const;
T& operator[]( I i );
T const &operator[]( I i ) const;
// Gets the root
I Root() const;
// Num elements
unsigned int Count() const;
// Max "size" of the vector
I MaxElement() const;
// Gets the children
I Parent( I i ) const;
I LeftChild( I i ) const;
I RightChild( I i ) const;
// Tests if a node is a left or right child
bool IsLeftChild( I i ) const;
bool IsRightChild( I i ) const;
// Tests if root or leaf
bool IsRoot( I i ) const;
bool IsLeaf( I i ) const;
// Checks if a node is valid and in the tree
bool IsValidIndex( I i ) const;
// Checks if the tree as a whole is valid
bool IsValid() const;
// Invalid index
static I InvalidIndex();
// returns the tree depth (not a very fast operation)
int Depth( I node ) const;
int Depth() const;
// Sets the less func
void SetLessFunc( LessFunc_t func );
// Allocation method
I NewNode();
// Insert method (inserts in order)
I Insert( T const &insert );
void Insert( const T *pArray, int nItems );
// Find method
I Find( T const &search ) const;
// Remove methods
void RemoveAt( I i );
bool Remove( T const &remove );
void RemoveAll( );
// Allocation, deletion
void FreeNode( I i );
// Iteration
I FirstInorder() const;
I NextInorder( I i ) const;
I PrevInorder( I i ) const;
I LastInorder() const;
I FirstPreorder() const;
I NextPreorder( I i ) const;
I PrevPreorder( I i ) const;
I LastPreorder( ) const;
I FirstPostorder() const;
I NextPostorder( I i ) const;
// If you change the search key, this can be used to reinsert the
// element into the tree.
void Reinsert( I elem );
protected:
enum NodeColor_t
{
RED = 0,
BLACK
};
struct Links_t
{
I m_Left;
I m_Right;
I m_Parent;
I m_Tag;
};
struct Node_t : public Links_t
{
T m_Data;
};
// Sets the children
void SetParent( I i, I parent );
void SetLeftChild( I i, I child );
void SetRightChild( I i, I child );
void LinkToParent( I i, I parent, bool isLeft );
// Gets at the links
Links_t const &Links( I i ) const;
Links_t &Links( I i );
// Checks if a link is red or black
bool IsRed( I i ) const;
bool IsBlack( I i ) const;
// Sets/gets node color
NodeColor_t Color( I i ) const;
void SetColor( I i, NodeColor_t c );
// operations required to preserve tree balance
void RotateLeft(I i);
void RotateRight(I i);
void InsertRebalance(I i);
void RemoveRebalance(I i);
// Insertion, removal
I InsertAt( I parent, bool leftchild );
// copy constructors not allowed
CUtlRBTree( CUtlRBTree<T, I> const &tree );
// Inserts a node into the tree, doesn't copy the data in.
void FindInsertionPosition( T const &insert, I &parent, bool &leftchild );
// Remove and add back an element in the tree.
void Unlink( I elem );
void Link( I elem );
// Used for sorting.
LessFunc_t m_LessFunc;
CUtlMemory<Node_t> m_Elements;
I m_Root;
I m_NumElements;
I m_FirstFree;
I m_TotalElements;
Node_t* m_pElements;
void ResetDbgInfo()
{
m_pElements = (Node_t*)m_Elements.Base();
}
};
//-----------------------------------------------------------------------------
// constructor, destructor
//-----------------------------------------------------------------------------
template <class T, class I>
CUtlRBTree<T, I>::CUtlRBTree( int growSize, int initSize, LessFunc_t lessfunc ) :
m_Elements( growSize, initSize ),
m_LessFunc( lessfunc ),
m_Root( InvalidIndex() ),
m_NumElements( 0 ), m_TotalElements( 0 ),
m_FirstFree( InvalidIndex() )
{
ResetDbgInfo();
}
template <class T, class I>
CUtlRBTree<T, I>::~CUtlRBTree()
{
}
//-----------------------------------------------------------------------------
// gets particular elements
//-----------------------------------------------------------------------------
template <class T, class I>
inline T &CUtlRBTree<T, I>::Element( I i )
{
return m_Elements[i].m_Data;
}
template <class T, class I>
inline T const &CUtlRBTree<T, I>::Element( I i ) const
{
return m_Elements[i].m_Data;
}
template <class T, class I>
inline T &CUtlRBTree<T, I>::operator[]( I i )
{
return Element(i);
}
template <class T, class I>
inline T const &CUtlRBTree<T, I>::operator[]( I i ) const
{
return Element(i);
}
//-----------------------------------------------------------------------------
//
// various accessors
//
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
// Gets the root
//-----------------------------------------------------------------------------
template <class T, class I>
inline I CUtlRBTree<T, I>::Root() const
{
return m_Root;
}
//-----------------------------------------------------------------------------
// Num elements
//-----------------------------------------------------------------------------
template <class T, class I>
inline unsigned int CUtlRBTree<T, I>::Count() const
{
return (unsigned int)m_NumElements;
}
//-----------------------------------------------------------------------------
// Max "size" of the vector
//-----------------------------------------------------------------------------
template <class T, class I>
inline I CUtlRBTree<T, I>::MaxElement() const
{
return (I)m_TotalElements;
}
//-----------------------------------------------------------------------------
// Gets the children
//-----------------------------------------------------------------------------
template <class T, class I>
inline I CUtlRBTree<T, I>::Parent( I i ) const
{
return Links(i).m_Parent;
}
template <class T, class I>
inline I CUtlRBTree<T, I>::LeftChild( I i ) const
{
return Links(i).m_Left;
}
template <class T, class I>
inline I CUtlRBTree<T, I>::RightChild( I i ) const
{
return Links(i).m_Right;
}
//-----------------------------------------------------------------------------
// Tests if a node is a left or right child
//-----------------------------------------------------------------------------
template <class T, class I>
inline bool CUtlRBTree<T, I>::IsLeftChild( I i ) const
{
return LeftChild(Parent(i)) == i;
}
template <class T, class I>
inline bool CUtlRBTree<T, I>::IsRightChild( I i ) const
{
return RightChild(Parent(i)) == i;
}
//-----------------------------------------------------------------------------
// Tests if root or leaf
//-----------------------------------------------------------------------------
template <class T, class I>
inline bool CUtlRBTree<T, I>::IsRoot( I i ) const
{
return i == m_Root;
}
template <class T, class I>
inline bool CUtlRBTree<T, I>::IsLeaf( I i ) const
{
return (LeftChild(i) == InvalidIndex()) && (RightChild(i) == InvalidIndex());
}
//-----------------------------------------------------------------------------
// Checks if a node is valid and in the tree
//-----------------------------------------------------------------------------
template <class T, class I>
inline bool CUtlRBTree<T, I>::IsValidIndex( I i ) const
{
return LeftChild(i) != i;
}
//-----------------------------------------------------------------------------
// Invalid index
//-----------------------------------------------------------------------------
template <class T, class I>
I CUtlRBTree<T, I>::InvalidIndex()
{
return (I)~0;
}
//-----------------------------------------------------------------------------
// returns the tree depth (not a very fast operation)
//-----------------------------------------------------------------------------
template <class T, class I>
inline int CUtlRBTree<T, I>::Depth() const
{
return Depth(Root());
}
//-----------------------------------------------------------------------------
// Sets the children
//-----------------------------------------------------------------------------
template <class T, class I>
inline void CUtlRBTree<T, I>::SetParent( I i, I parent )
{
Links(i).m_Parent = parent;
}
template <class T, class I>
inline void CUtlRBTree<T, I>::SetLeftChild( I i, I child )
{
Links(i).m_Left = child;
}
template <class T, class I>
inline void CUtlRBTree<T, I>::SetRightChild( I i, I child )
{
Links(i).m_Right = child;
}
//-----------------------------------------------------------------------------
// Gets at the links
//-----------------------------------------------------------------------------
static const int s_Sentinel[4] = {-1, -1, -1, 1};
template <class T, class I>
inline typename CUtlRBTree<T, I>::Links_t const &CUtlRBTree<T, I>::Links( I i ) const
{
// Sentinel node, makes life easier
return (i != InvalidIndex()) ? *(Links_t*)&m_Elements[i] :
*(Links_t*)&s_Sentinel;
}
template <class T, class I>
inline typename CUtlRBTree<T, I>::Links_t &CUtlRBTree<T, I>::Links( I i )
{
Assert(i != InvalidIndex());
return *(Links_t *)&m_Elements[i];
}
//-----------------------------------------------------------------------------
// Checks if a link is red or black
//-----------------------------------------------------------------------------
template <class T, class I>
inline bool CUtlRBTree<T, I>::IsRed( I i ) const
{
return (Links(i).m_Tag == RED);
}
template <class T, class I>
inline bool CUtlRBTree<T, I>::IsBlack( I i ) const
{
return (Links(i).m_Tag == BLACK);
}
//-----------------------------------------------------------------------------
// Sets/gets node color
//-----------------------------------------------------------------------------
template <class T, class I>
inline typename CUtlRBTree<T, I>::NodeColor_t CUtlRBTree<T, I>::Color( I i ) const
{
return (NodeColor_t)Links(i).m_Tag;
}
template <class T, class I>
inline void CUtlRBTree<T, I>::SetColor( I i, typename CUtlRBTree<T, I>::NodeColor_t c )
{
Links(i).m_Tag = (I)c;
}
//-----------------------------------------------------------------------------
// Allocates/ deallocates nodes
//-----------------------------------------------------------------------------
template <class T, class I>
I CUtlRBTree<T, I>::NewNode()
{
I newElem;
// Nothing in the free list; add.
if (m_FirstFree == InvalidIndex())
{
if (m_Elements.NumAllocated() == m_TotalElements)
m_Elements.Grow();
newElem = m_TotalElements++;
}
else
{
newElem = m_FirstFree;
m_FirstFree = RightChild(m_FirstFree);
}
#ifdef _DEBUG
// reset links to invalid....
Links_t &node = Links(newElem);
node.m_Left = node.m_Right = node.m_Parent = InvalidIndex();
#endif
Construct( &Element(newElem) );
ResetDbgInfo();
return newElem;
}
template <class T, class I>
void CUtlRBTree<T, I>::FreeNode( I i )
{
Assert( IsValidIndex(i) && (i != InvalidIndex()) );
Destruct( &Element(i) );
SetLeftChild( i, i ); // indicates it's in not in the tree
SetRightChild( i, m_FirstFree );
m_FirstFree = i;
}
//-----------------------------------------------------------------------------
// Rotates node i to the left
//-----------------------------------------------------------------------------
template <class T, class I>
void CUtlRBTree<T, I>::RotateLeft(I elem)
{
I rightchild = RightChild(elem);
SetRightChild( elem, LeftChild(rightchild) );
if (LeftChild(rightchild) != InvalidIndex())
SetParent( LeftChild(rightchild), elem );
if (rightchild != InvalidIndex())
SetParent( rightchild, Parent(elem) );
if (!IsRoot(elem))
{
if (IsLeftChild(elem))
SetLeftChild( Parent(elem), rightchild );
else
SetRightChild( Parent(elem), rightchild );
}
else
m_Root = rightchild;
SetLeftChild( rightchild, elem );
if (elem != InvalidIndex())
SetParent( elem, rightchild );
}
//-----------------------------------------------------------------------------
// Rotates node i to the right
//-----------------------------------------------------------------------------
template <class T, class I>
void CUtlRBTree<T, I>::RotateRight(I elem)
{
I leftchild = LeftChild(elem);
SetLeftChild( elem, RightChild(leftchild) );
if (RightChild(leftchild) != InvalidIndex())
SetParent( RightChild(leftchild), elem );
if (leftchild != InvalidIndex())
SetParent( leftchild, Parent(elem) );
if (!IsRoot(elem))
{
if (IsRightChild(elem))
SetRightChild( Parent(elem), leftchild );
else
SetLeftChild( Parent(elem), leftchild );
}
else
m_Root = leftchild;
SetRightChild( leftchild, elem );
if (elem != InvalidIndex())
SetParent( elem, leftchild );
}
//-----------------------------------------------------------------------------
// Rebalances the tree after an insertion
//-----------------------------------------------------------------------------
template <class T, class I>
void CUtlRBTree<T, I>::InsertRebalance(I elem)
{
while ( !IsRoot(elem) && (Color(Parent(elem)) == RED) )
{
I parent = Parent(elem);
I grandparent = Parent(parent);
/* we have a violation */
if (IsLeftChild(parent))
{
I uncle = RightChild(grandparent);
if (IsRed(uncle))
{
/* uncle is RED */
SetColor(parent, BLACK);
SetColor(uncle, BLACK);
SetColor(grandparent, RED);
elem = grandparent;
}
else
{
/* uncle is BLACK */
if (IsRightChild(elem))
{
/* make x a left child, will change parent and grandparent */
elem = parent;
RotateLeft(elem);
parent = Parent(elem);
grandparent = Parent(parent);
}
/* recolor and rotate */
SetColor(parent, BLACK);
SetColor(grandparent, RED);
RotateRight(grandparent);
}
}
else
{
/* mirror image of above code */
I uncle = LeftChild(grandparent);
if (IsRed(uncle))
{
/* uncle is RED */
SetColor(parent, BLACK);
SetColor(uncle, BLACK);
SetColor(grandparent, RED);
elem = grandparent;
}
else
{
/* uncle is BLACK */
if (IsLeftChild(elem))
{
/* make x a right child, will change parent and grandparent */
elem = parent;
RotateRight(parent);
parent = Parent(elem);
grandparent = Parent(parent);
}
/* recolor and rotate */
SetColor(parent, BLACK);
SetColor(grandparent, RED);
RotateLeft(grandparent);
}
}
}
SetColor( m_Root, BLACK );
}
//-----------------------------------------------------------------------------
// Insert a node into the tree
//-----------------------------------------------------------------------------
template <class T, class I>
I CUtlRBTree<T, I>::InsertAt( I parent, bool leftchild )
{
I i = NewNode();
LinkToParent( i, parent, leftchild );
++m_NumElements;
return i;
}
template <class T, class I>
void CUtlRBTree<T, I>::LinkToParent( I i, I parent, bool isLeft )
{
Links_t &elem = Links(i);
elem.m_Parent = parent;
elem.m_Left = elem.m_Right = InvalidIndex();
elem.m_Tag = RED;
/* insert node in tree */
if (parent != InvalidIndex())
{
if (isLeft)
Links(parent).m_Left = i;
else
Links(parent).m_Right = i;
}
else
{
m_Root = i;
}
InsertRebalance(i);
Assert(IsValid());
}
//-----------------------------------------------------------------------------
// Rebalance the tree after a deletion
//-----------------------------------------------------------------------------
template <class T, class I>
void CUtlRBTree<T, I>::RemoveRebalance(I elem)
{
while (elem != m_Root && IsBlack(elem))
{
I parent = Parent(elem);
// If elem is the left child of the parent
if (elem == LeftChild(parent))
{
// Get our sibling
I sibling = RightChild(parent);
if (IsRed(sibling))
{
SetColor(sibling, BLACK);
SetColor(parent, RED);
RotateLeft(parent);
// We may have a new parent now
parent = Parent(elem);
sibling = RightChild(parent);
}
if ( (IsBlack(LeftChild(sibling))) && (IsBlack(RightChild(sibling))) )
{
if (sibling != InvalidIndex())
SetColor(sibling, RED);
elem = parent;
}
else
{
if (IsBlack(RightChild(sibling)))
{
SetColor(LeftChild(sibling), BLACK);
SetColor(sibling, RED);
RotateRight(sibling);
// rotation may have changed this
parent = Parent(elem);
sibling = RightChild(parent);
}
SetColor( sibling, Color(parent) );
SetColor( parent, BLACK );
SetColor( RightChild(sibling), BLACK );
RotateLeft( parent );
elem = m_Root;
}
}
else
{
// Elem is the right child of the parent
I sibling = LeftChild(parent);
if (IsRed(sibling))
{
SetColor(sibling, BLACK);
SetColor(parent, RED);
RotateRight(parent);
// We may have a new parent now
parent = Parent(elem);
sibling = LeftChild(parent);
}
if ( (IsBlack(RightChild(sibling))) && (IsBlack(LeftChild(sibling))) )
{
if (sibling != InvalidIndex())
SetColor( sibling, RED );
elem = parent;
}
else
{
if (IsBlack(LeftChild(sibling)))
{
SetColor( RightChild(sibling), BLACK );
SetColor( sibling, RED );
RotateLeft( sibling );
// rotation may have changed this
parent = Parent(elem);
sibling = LeftChild(parent);
}
SetColor( sibling, Color(parent) );
SetColor( parent, BLACK );
SetColor( LeftChild(sibling), BLACK );
RotateRight( parent );
elem = m_Root;
}
}
}
SetColor( elem, BLACK );
}
template <class T, class I>
void CUtlRBTree<T, I>::Unlink( I elem )
{
if ( elem != InvalidIndex() )
{
I x, y;
if ((LeftChild(elem) == InvalidIndex()) ||
(RightChild(elem) == InvalidIndex()))
{
/* y has a NIL node as a child */
y = elem;
}
else
{
/* find tree successor with a NIL node as a child */
y = RightChild(elem);
while (LeftChild(y) != InvalidIndex())
y = LeftChild(y);
}
/* x is y's only child */
if (LeftChild(y) != InvalidIndex())
x = LeftChild(y);
else
x = RightChild(y);
/* remove y from the parent chain */
if (x != InvalidIndex())
SetParent( x, Parent(y) );
if (!IsRoot(y))
{
if (IsLeftChild(y))
SetLeftChild( Parent(y), x );
else
SetRightChild( Parent(y), x );
}
else
m_Root = x;
// need to store this off now, we'll be resetting y's color
NodeColor_t ycolor = Color(y);
if (y != elem)
{
// Standard implementations copy the data around, we cannot here.
// Hook in y to link to the same stuff elem used to.
SetParent( y, Parent(elem) );
SetRightChild( y, RightChild(elem) );
SetLeftChild( y, LeftChild(elem) );
if (!IsRoot(elem))
if (IsLeftChild(elem))
SetLeftChild( Parent(elem), y );
else
SetRightChild( Parent(elem), y );
else
m_Root = y;
if (LeftChild(y) != InvalidIndex())
SetParent( LeftChild(y), y );
if (RightChild(y) != InvalidIndex())
SetParent( RightChild(y), y );
SetColor( y, Color(elem) );
}
if ((x != InvalidIndex()) && (ycolor == BLACK))
RemoveRebalance(x);
}
}
template <class T, class I>
void CUtlRBTree<T, I>::Link( I elem )
{
if ( elem != InvalidIndex() )
{
I parent;
bool leftchild;
FindInsertionPosition( Element( elem ), parent, leftchild );
LinkToParent( elem, parent, leftchild );
}
}
//-----------------------------------------------------------------------------
// Delete a node from the tree
//-----------------------------------------------------------------------------
template <class T, class I>
void CUtlRBTree<T, I>::RemoveAt(I elem)
{
if ( elem != InvalidIndex() )
{
Unlink( elem );
FreeNode(elem);
--m_NumElements;
}
}
//-----------------------------------------------------------------------------
// remove a node in the tree
//-----------------------------------------------------------------------------
template <class T, class I> bool CUtlRBTree<T, I>::Remove( T const &search )
{
I node = Find( search );
if (node != InvalidIndex())
{
RemoveAt(node);
return true;
}
return false;
}
//-----------------------------------------------------------------------------
// Removes all nodes from the tree
//-----------------------------------------------------------------------------
template <class T, class I>
void CUtlRBTree<T, I>::RemoveAll()
{
// Just iterate through the whole list and add to free list
// much faster than doing all of the rebalancing
// also, do it so the free list is pointing to stuff in order
// to get better cache coherence when re-adding stuff to this tree.
I prev = InvalidIndex();
for (int i = (int)m_TotalElements; --i >= 0; )
{
I idx = (I)i;
if (IsValidIndex(idx))
Destruct( &Element(idx) );
SetRightChild( idx, prev );
SetLeftChild( idx, idx );
prev = idx;
}
m_FirstFree = m_TotalElements ? (I)0 : InvalidIndex();
m_Root = InvalidIndex();
m_NumElements = 0;
}
//-----------------------------------------------------------------------------
// iteration
//-----------------------------------------------------------------------------
template <class T, class I>
I CUtlRBTree<T, I>::FirstInorder() const
{
I i = m_Root;
while (LeftChild(i) != InvalidIndex())
i = LeftChild(i);
return i;
}
template <class T, class I>
I CUtlRBTree<T, I>::NextInorder( I i ) const
{
Assert(IsValidIndex(i));
if (RightChild(i) != InvalidIndex())
{
i = RightChild(i);
while (LeftChild(i) != InvalidIndex())
i = LeftChild(i);
return i;
}
I parent = Parent(i);
while (IsRightChild(i))
{
i = parent;
if (i == InvalidIndex()) break;
parent = Parent(i);
}
return parent;
}
template <class T, class I>
I CUtlRBTree<T, I>::PrevInorder( I i ) const
{
Assert(IsValidIndex(i));
if (LeftChild(i) != InvalidIndex())
{
i = LeftChild(i);
while (RightChild(i) != InvalidIndex())
i = RightChild(i);
return i;
}
I parent = Parent(i);
while (IsLeftChild(i))
{
i = parent;
if (i == InvalidIndex()) break;
parent = Parent(i);
}
return parent;
}
template <class T, class I>
I CUtlRBTree<T, I>::LastInorder() const
{
I i = m_Root;
while (RightChild(i) != InvalidIndex())
i = RightChild(i);
return i;
}
template <class T, class I>
I CUtlRBTree<T, I>::FirstPreorder() const
{
return m_Root;
}
template <class T, class I>
I CUtlRBTree<T, I>::NextPreorder( I i ) const
{
if (LeftChild(i) != InvalidIndex())
return LeftChild(i);
if (RightChild(i) != InvalidIndex())
return RightChild(i);
I parent = Parent(i);
while( parent != InvalidIndex())
{
if (IsLeftChild(i) && (RightChild(parent) != InvalidIndex()))
return RightChild(parent);
i = parent;
parent = Parent(parent);
}
return InvalidIndex();
}
template <class T, class I>
I CUtlRBTree<T, I>::PrevPreorder( I i ) const
{
Assert(0); // not implemented yet
return InvalidIndex();
}
template <class T, class I>
I CUtlRBTree<T, I>::LastPreorder() const
{
I i = m_Root;
while (1)
{
while (RightChild(i) != InvalidIndex())
i = RightChild(i);
if (LeftChild(i) != InvalidIndex())
i = LeftChild(i);
else
break;
}
return i;
}
template <class T, class I>
I CUtlRBTree<T, I>::FirstPostorder() const
{
I i = m_Root;
while (!IsLeaf(i))
{
if (LeftChild(i))
i = LeftChild(i);
else
i = RightChild(i);
}
return i;
}
template <class T, class I>
I CUtlRBTree<T, I>::NextPostorder( I i ) const
{
I parent = Parent(i);
if (parent == InvalidIndex())
return InvalidIndex();
if (IsRightChild(i))
return parent;
if (RightChild(parent) == InvalidIndex())
return parent;
i = RightChild(parent);
while (!IsLeaf(i))
{
if (LeftChild(i))
i = LeftChild(i);
else
i = RightChild(i);
}
return i;
}
template <class T, class I>
void CUtlRBTree<T, I>::Reinsert( I elem )
{
Unlink( elem );
Link( elem );
}
//-----------------------------------------------------------------------------
// returns the tree depth (not a very fast operation)
//-----------------------------------------------------------------------------
#ifdef max
#undef max
#endif
#define max(a,b) (a)>(b)?(a):(b)
template <class T, class I>
int CUtlRBTree<T, I>::Depth( I node ) const
{
if (node == InvalidIndex())
return 0;
int depthright = Depth( RightChild(node) );
int depthleft = Depth( LeftChild(node) );
return max(depthright, depthleft) + 1;
}
//-----------------------------------------------------------------------------
// Makes sure the tree is valid after every operation
//-----------------------------------------------------------------------------
template <class T, class I>
bool CUtlRBTree<T, I>::IsValid() const
{
if ( !Count() )
return true;
if (( Root() >= MaxElement()) || ( Parent( Root() ) != InvalidIndex() ))
goto InvalidTree;
#ifdef UTLTREE_PARANOID
// First check to see that mNumEntries matches reality.
// count items on the free list
int numFree = 0;
int curr = m_FirstFree;
while (curr != InvalidIndex())
{
++numFree;
curr = RightChild(curr);
if ( (curr > MaxElement()) && (curr != InvalidIndex()) )
goto InvalidTree;
}
if (MaxElement() - numFree != Count())
goto InvalidTree;
// iterate over all elements, looking for validity
// based on the self pointers
int numFree2 = 0;
for (curr = 0; curr < MaxElement(); ++curr)
{
if (!IsValidIndex(curr))
++numFree2;
else
{
int right = RightChild(curr);
int left = LeftChild(curr);
if ((right == left) && (right != InvalidIndex()) )
goto InvalidTree;
if (right != InvalidIndex())
{
if (!IsValidIndex(right))
goto InvalidTree;
if (Parent(right) != curr)
goto InvalidTree;
if (IsRed(curr) && IsRed(right))
goto InvalidTree;
}
if (left != InvalidIndex())
{
if (!IsValidIndex(left))
goto InvalidTree;
if (Parent(left) != curr)
goto InvalidTree;
if (IsRed(curr) && IsRed(left))
goto InvalidTree;
}
}
}
if (numFree2 != numFree)
goto InvalidTree;
#endif // UTLTREE_PARANOID
return true;
InvalidTree:
return false;
}
//-----------------------------------------------------------------------------
// Sets the less func
//-----------------------------------------------------------------------------
template <class T, class I>
void CUtlRBTree<T, I>::SetLessFunc( typename CUtlRBTree<T, I>::LessFunc_t func )
{
if (!m_LessFunc)
m_LessFunc = func;
else
{
// need to re-sort the tree here....
Assert(0);
}
}
//-----------------------------------------------------------------------------
// inserts a node into the tree
//-----------------------------------------------------------------------------
// Inserts a node into the tree, doesn't copy the data in.
template <class T, class I>
void CUtlRBTree<T, I>::FindInsertionPosition( T const &insert, I &parent, bool &leftchild )
{
Assert( m_LessFunc != NULL );
/* find where node belongs */
I current = m_Root;
parent = InvalidIndex();
leftchild = false;
while (current != InvalidIndex())
{
parent = current;
if (m_LessFunc( insert, Element(current) ))
{
leftchild = true; current = LeftChild(current);
}
else
{
leftchild = false; current = RightChild(current);
}
}
}
template <class T, class I>
I CUtlRBTree<T, I>::Insert( T const &insert )
{
// use copy constructor to copy it in
I parent;
bool leftchild;
FindInsertionPosition( insert, parent, leftchild );
I newNode = InsertAt( parent, leftchild );
CopyConstruct( &Element( newNode ), insert );
return newNode;
}
template <class T, class I>
void CUtlRBTree<T, I>::Insert( const T *pArray, int nItems )
{
while ( nItems-- )
{
Insert( *pArray++ );
}
}
//-----------------------------------------------------------------------------
// finds a node in the tree
//-----------------------------------------------------------------------------
template <class T, class I>
I CUtlRBTree<T, I>::Find( T const &search ) const
{
Assert( m_LessFunc != NULL );
I current = m_Root;
while (current != InvalidIndex())
{
if (m_LessFunc( search, Element(current) ))
current = LeftChild(current);
else if (m_LessFunc( Element(current), search ))
current = RightChild(current);
else
break;
}
return current;
}
#endif//UTLRBTREE_H