红黑树实现文件C语言

  这个东西,保证了树的深度很低,而且旋转的次数很少.较同类的AVL树有了很大的提高.但是实现起来,并不简单.

  好吧,继续我的习惯,代码说明问题.

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/*RedBlackTree.c -- 红黑树实现文件*/#include "RedBlackTree.h"/*全局变量引用*/extern Node * NullNode ;extern Node * Current, * Sibling, * Parent, * GrParent, * GrGrParent ;/*局部函数声明*/static Node * singleRotateWithLeft (Node * const parent) ;static Node * singleRotateWithRight (Node * const parent) ;static Node * rotate (Node * const parent, const Item item) ;static void handleReorient (RedBlackTree * const prbt, const Item item) ;static void changeColor (void) ;static void traversal (const Node * const pn, void (* pfun) (const Node * const pn)) ;static void release (Node * const pn) ;/*接口函数定义*//*(*prbt) -> root -> right is the real root instead of (*prbt) -> root.*/BOOL Create_R (RedBlackTree * const prbt){NullNode = (Node *) malloc (sizeof (Node)) ;if (NULL == NullNode)return FALSE ;*prbt = (struct redBlackTree *) malloc (sizeof (struct redBlackTree)) ;if (NULL == *prbt){free (NullNode) ;NullNode = NULL ;return FALSE ;}(*prbt) -> root = (Node *) malloc (sizeof (Node)) ;if (NULL == (*prbt) -> root){free (NullNode) ;NullNode = NULL ;free (*prbt) ;}NullNode -> item = INFINITY ;NullNode -> left = NullNode -> right = NullNode ;NullNode -> color = Black ;(*prbt) -> root -> item = NEGATIVE_INFINITY ;(*prbt) -> root -> left = (*prbt) -> root -> right = NullNode ;(*prbt) -> root -> color = Black ;(*prbt) -> current = 0 ;return TRUE ;}BOOL IsEmpty_R (const RedBlackTree * const prbt){if (0 == (*prbt) -> current)return TRUE ;elsereturn FALSE ;}BOOL Insert_R (RedBlackTree * const prbt, const Item item){Node * newNode ;GrParent = Parent = Current = (*prbt) -> root ;NullNode -> item = item ;while (Current -> item != item){GrGrParent = GrParent ;GrParent = Parent ;Parent = Current ;if (item < Current -> item)Current = Current -> left ;elseCurrent = Current -> right ;if (Red == Current -> left -> color && Red == Current -> right -> color)handleReorient (prbt, item) ;}if (Current != NullNode)return FALSE ;newNode = (Node *) malloc (sizeof (Node)) ;if (NULL == newNode)return FALSE ;newNode -> item = item ;newNode -> left = newNode -> right = NullNode ;if (item < Parent -> item)Parent -> left = newNode ;elseParent -> right = newNode ;Current = newNode ;handleReorient (prbt, item) ;(*prbt) -> current++ ;return TRUE ;}/*The central idea is go to delete a red leaf.*/BOOL Delete_R (RedBlackTree * const prbt, const Item item){BOOL found = FALSE ;Node * record ;Item scapegoat ;int temp ;if (IsEmpty_R (prbt))return FALSE ;Current = (*prbt) -> root ;/*First, look for it.*/while (Current != NullNode){if (item == Current -> item){found = TRUE ;record = Current ;break ;}else if (item < Current -> item){Parent = Current ;Current = Current -> left ;}else{Parent = Current ;Current = Current -> right ;}}/*If not found.*/if (FALSE == found)return FALSE ;if (Current -> right != NullNode){Parent = Current ;Current = Parent -> right ;scapegoat = Current -> item ;/*Without optimizing it.*/while (Current -> left != NullNode){Parent = Current ;Current = Current -> left ;scapegoat = Current -> item ;}/*Make it be a lead.*/if (Current -> right != NullNode){temp = Current -> color ;Current -> color = Current -> right -> color ;Current -> right -> color = temp ;Parent -> left = singleRotateWithRight (Current) ;}}else if (Current -> left != NullNode){Parent = Current ;Current = Parent -> left ;scapegoat = Current -> item ;while (Current -> right != NullNode){Parent = Current ;Current = Current -> right ;scapegoat = Current -> item ;}if (Current -> left != NullNode){temp = Current -> color ;Current -> color = Current -> left -> color ;Current -> left -> color = temp ;Parent -> right = singleRotateWithLeft (Current) ;}}/*If Current is a leaf.*/else{/*If current is a red leaf.*/if (Red == Current -> color){if (Current == Parent -> left)Parent -> left = NullNode ;elseParent -> right = NullNode ;free (Current) ;(*prbt) -> current-- ;return TRUE ;}elsescapegoat = Current -> item ;}/*Next hasn't be integrated.*/(*prbt) -> root -> color = Red ;Current = (*prbt) -> root ;/*Make sure NullNode -> item hasn't appear in the tree.*/NullNode -> item = (*prbt) -> root -> item ;/*Core loop.*/while (Current -> item != scapegoat){if (scapegoat < Current -> item){/*Updata node.*/GrParent = Parent ;Parent = Current ;Current = Parent -> left ;Sibling = Parent -> right ;/*If Current has a leaf at least.*/if (Red == Current -> left -> color || Red == Current -> right -> color){if (scapegoat < Current -> item){/*If Current drops onto a black node.*/if (Black == Current -> left -> color){Current -> color = Red ;Current -> right -> color = Black ;Parent -> left = singleRotateWithRight (Current) ;}/*If Current drops on to a red node, update node and continue.*/else{GrParent = Parent ;Parent = Current ;Current = Parent -> left ;Sibling = Parent -> right ;continue ;}}else{/*If Current drops onto a black node.*/if (Black == Current -> right -> color){Current -> color = Red ;Current -> left -> color = Black ;Parent -> left = singleRotateWithLeft (Current) ;}/*If Current drops on to a red node, update node and continue.*/else{GrParent = Parent ;Parent = Current ;Current = Parent -> right ;Sibling = Parent -> left ;continue ;}}}/*If Current has two black children.*/if (Black == Current -> left -> color && Black == Current -> right -> color){/*If Sibling's left child is red.*/if (Red == Sibling -> left -> color){Parent -> right = singleRotateWithLeft (Sibling) ;Parent -> color = Black ;Current -> color = Red ;if (Parent == GrParent -> left)GrParent -> left = singleRotateWithRight (Parent) ;elseGrParent -> right = singleRotateWithRight (Parent) ;}/*If Sibling's right child is red.*/else if (Red == Sibling -> right -> color){Parent -> color = Black ;Sibling -> right -> color = Black ;Sibling -> color = Red ;Current -> color = Red ;if (Parent == GrParent -> left)GrParent -> left = singleRotateWithRight (Parent) ;elseGrParent -> right = singleRotateWithRight (Parent) ;}/*If Sibling has two black children.*/elsechangeColor () ;}}/*The circumstances of whirling has a little strange.*/else{GrParent = Parent ;Parent = Current ;Current = Parent -> right ;Sibling = Parent -> left ;if (Red == Current -> left -> color || Red == Current -> right -> color){if (scapegoat < Current -> item){if (Black == Current -> left -> color){Current -> color = Red ;Current -> right -> color = Black ;Parent -> right = singleRotateWithRight (Current) ;}else{GrParent = Parent ;Parent = Current ;Current = Parent -> left ;Sibling = Parent -> right ;continue ;}}else{if (Black == Current -> right -> color){Current -> color = Red ;Current -> left -> color = Black ;Parent -> left = singleRotateWithLeft (Current) ;}else{GrParent = Parent ;Parent = Current ;Current = Parent -> right ;Sibling = Parent -> left ;continue ;}}}if (Black == Current -> left -> color && Black == Current -> right -> color){if (Red == Sibling -> left -> color){Parent -> color = Black ;Sibling -> left -> color = Black ;Sibling -> color = Red ;Current -> color = Red ;if (Parent == GrParent -> left)GrParent -> left = singleRotateWithLeft (Parent) ;elseGrParent -> right = singleRotateWithLeft (Parent) ;}else if (Red == Sibling -> right -> color){Parent -> left = singleRotateWithRight (Sibling) ;Parent -> color = Black ;Current -> color = Red ;if (Parent == GrParent -> left)GrParent -> left = singleRotateWithLeft (Parent) ;elseGrParent -> right = singleRotateWithLeft (Parent) ;}else{changeColor () ;if (Red == NullNode -> color){putchar ('/a') ;NullNode -> color = Black ;}}}}}/*Replace.*/record -> item = scapegoat ;if (scapegoat == Parent -> left -> item)Parent -> left = NullNode ;elseParent -> right = NullNode ;free (Current) ;(*prbt) -> root -> color = Black ;(*prbt) -> root -> right -> color = Black ;(*prbt) -> current-- ;return TRUE ;}void Traversal_R (const RedBlackTree * const prbt, void (* pfun) (const Node * const pn)){traversal ((*prbt) -> root -> right, pfun) ;putchar ('/n') ;}void Release_R (const RedBlackTree * const prbt){release ((*prbt) -> root -> right) ;free ((*prbt) -> root) ;free (*prbt) ;free (NullNode) ;}/*局部函数定义*//*child will become the new root of the subtree.*/static Node * singleRotateWithLeft (Node * const parent){Node * child ;child = parent -> left ;parent -> left = child -> right ;child -> right = parent ;return child ;}static Node * singleRotateWithRight (Node * const parent){Node * child ;child = parent -> right ;parent -> right = child -> left ;child -> left = parent ;return child ;}static Node * rotate (Node * const parent, const Item item){if (item < parent -> item){return parent -> left = item < parent -> left -> item ?singleRotateWithLeft (parent -> left): singleRotateWithRight (parent -> left) ;}else{return parent -> right = item < parent -> right -> item ?singleRotateWithLeft (parent -> right): singleRotateWithRight (parent -> right) ;}}static void handleReorient (RedBlackTree * const prbt, const Item item){Current -> color = Red ;Current -> left -> color = Current -> right -> color = Black ;if (Red == Parent -> color){GrParent -> color = Red ;if ((item < GrParent -> item) != (item < Parent -> item))Parent = rotate (GrParent, item) ;Current = rotate (GrGrParent, item) ;Current -> color = Black ;}(*prbt) -> root -> right -> color = Black ;}/*Won't change NullNode's color.*/static void changeColor (void){if (Parent -> left != NullNode)Parent -> left -> color = Red ;Parent -> color = Black ;Parent -> right -> color = Red ;}static void traversal (const Node * const pn, void (* pfun) (const Node * const pn)){if (pn != NullNode){traversal (pn -> left, pfun) ;(* pfun) (pn) ;traversal (pn -> right, pfun) ;}}static void release (Node * const pn){if (pn != NullNode){release (pn -> left) ;release (pn -> right) ;free (pn) ;}}