Complete and nicely-interfaced generic avl tree implementation.

This commit is contained in:
HyperAssembler 2015-03-01 01:11:58 -08:00
parent 3f7297a2a7
commit f4995007c1
2 changed files with 302 additions and 204 deletions

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@ -1,228 +1,325 @@
#include "type.h"
#include "kdef.h"
#include "avl_tree.h"
#include <stdlib.h>
int64_t NATIVE64 _max(int64_t a, int64_t b)
#define MAX(a, b) (((a) > (b) ? (a) : (b)))
// internal
int inline _get_height(avl_tree *node)
{
return (a > b)? a : b;
return node == NULL ? -1 : node->height;
}
int64_t NATIVE64 _get_height(void * root, int64_t (*get_height)(void*))
{
if(root == NULL)
return -1;
return get_height(root);
}
void *NATIVE64 _right_rotate(void *y,
void *(*get_left)(void *),
void (*set_left)(void *, void *),
void *(*get_right)(void *),
void(*set_right)(void *, void *),
int64_t (*get_height)(void *),
void(*set_height)(void *, int64_t))
{
void *x = get_left(y);
void *T2 = get_right(x);
// Perform rotation
set_right(x,y);
set_left(y,T2);
// Update heights
set_height(y,_max(_get_height(get_left(y),get_height), _get_height(get_right(y),get_height))+1);
set_height(x,_max(_get_height(get_left(x),get_height), _get_height(get_right(x),get_height))+1);
// Return new root
return x;
}
void *NATIVE64 _left_rotate(void *x,
void *(*get_left)(void *),
void (*set_left)(void *, void *),
void *(*get_right)(void *),
void(*set_right)(void *, void *),
int64_t (*get_height)(void *),
void(*set_height)(void *, int64_t))
{
void *y = get_right(x);
void *T2 = get_left(y);
// Perform rotation
set_left(y,x);
set_right(x,T2);
// Update heights
set_height(x, _max(_get_height(get_left(x),get_height), _get_height(get_right(x),get_height))+1);
set_height(y, _max(_get_height(get_left(y),get_height), _get_height(get_right(y),get_height))+1);
// Return new root
return y;
}
// Get Balance factor of node N
int64_t NATIVE64 _get_balance_factor(void *node,
void *(*get_left)(void *),
void *(*get_right)(void *),
int64_t (*get_height)(void *))
int _balance_factor(avl_tree *node)
{
if (node == NULL)
return 0;
return _get_height(get_left(node),get_height) - _get_height(get_right(node),get_height);
return _get_height(node->left) - _get_height(node->right);
}
void*NATIVE64 avl_insert_node(void *node, void *key,
void *(*get_left)(void *),
void (*set_left)(void *, void *),
void *(*get_right)(void *),
void(*set_right)(void *, void *),
int64_t (*get_height)(void *),
void(*set_height)(void *, int64_t),
int (*compare)(void *, void *))
avl_tree *_right_rotate(avl_tree *root)
{
/* 1. Perform the normal BST rotation */
if (node == NULL)
return key;
if (compare(key,node) < 0)
set_left(node, avl_insert_node(get_left(node), key, get_left, set_left, get_right, set_right, get_height, set_height, compare));
else if (compare(key,node) == 0)
return node;
avl_tree *left_children = root->left;
//adjust parents first
left_children->parent = root->parent;
root->parent = left_children;
if (left_children->right != NULL)
left_children->right->parent = root;
//perform rotation
root->left = root->left->right;
left_children->right = root;
//adjust height
root->height = MAX(_get_height(root->left), _get_height(root->right)) + 1;
left_children->height = MAX(_get_height(left_children->left), _get_height(left_children->right)) + 1;
return left_children;
}
avl_tree *_left_rotate(avl_tree *root)
{
avl_tree *right_children = root->right;
//adjust parents
right_children->parent = root->parent;
root->parent = right_children;
if (right_children->left != NULL)
right_children->left->parent = root;
//perform rotation
root->right = root->right->left;
right_children->left = root;
root->height = MAX(_get_height(root->left), _get_height(root->right)) + 1;
right_children->height = MAX(_get_height(right_children->left), _get_height(right_children->right)) + 1;
return right_children;
}
avl_tree *_balance_node(avl_tree *node)
{
const int bf = _balance_factor(node);
if (bf > 1)
{
const int left_bf = _balance_factor(node->left);
if (left_bf >= 0)
//left left
return _right_rotate(node);
else
{
//left right
node->left = _left_rotate(node->left);
return _right_rotate(node);
}
}
else if (bf < -1)
{
const int right_bf = _balance_factor(node->right);
if (right_bf <= 0)
{
// right right
return _left_rotate(node);
}
else
{
// right left
node->right = _right_rotate(node->right);
return _left_rotate(node);
}
}
else
set_right(node, avl_insert_node(get_right(node), key, get_left, set_left, get_right, set_right, get_height, set_height, compare));
return node;
/* 2. Update height of this ancestor node */
set_height(node, _max(_get_height(get_left(node),get_height), _get_height(get_right(node),get_height)) + 1);
/* 3. Get the balance factor of this ancestor node to check whether
this node became unbalanced */
int64_t balance = _get_balance_factor(node, get_left, get_right, get_height);
// If this node becomes unbalanced, then there are 4 cases
// Left Left Case
if (balance > 1 && compare(key, get_left(node)) < 0)
return _right_rotate(node,get_left,set_left,get_right,set_right,get_height,set_height);
// Right Right Case
if (balance < -1 && compare(key, get_right(node)) > 0)
return _left_rotate(node,get_left,set_left,get_right,set_right,get_height,set_height);
// Left Right Case
if (balance > 1 && compare(key, get_left(node)) > 0)
{
set_left(node, _left_rotate(get_left(node),get_left,set_left,get_right,set_right,get_height,set_height));
return _right_rotate(node,get_left,set_left,get_right,set_right,get_height,set_height);
}
// Right Left Case
if (balance < -1 && compare(key, get_right(node)) < 0)
{
set_right(node, _right_rotate(get_right(node),get_left,set_left,get_right,set_right,get_height,set_height));
return _left_rotate(node,get_left,set_left,get_right,set_right,get_height,set_height);
}
/* return the (unchanged) node pointer */
return node;
}
void*NATIVE64 avl_delete_node(void *root, void *key,
void *(*get_left)(void *),
void (*set_left)(void *, void *),
void *(*get_right)(void *),
void(*set_right)(void *, void *),
int64_t (*get_height)(void *),
void(*set_height)(void *, int64_t),
int (*compare)(void *, void *),
void (*set_data)(void *, void *))
avl_tree *_create()
{
// STEP 1: PERFORM STANDARD BST DELETE
if (root == NULL)
avl_tree *tree = (avl_tree *) (malloc(sizeof(avl_tree)));
tree->parent = NULL;
tree->data = NULL;
tree->right = NULL;
tree->left = NULL;
tree->height = 0;
return tree;
}
avl_tree *_insert(avl_tree *root, void *data, int(*compare)(void *, void *), avl_tree *parent)
{
if (data == NULL)
return root;
if (root == NULL)
{
avl_tree *tree = _create();
tree->data = data;
tree->parent = parent;
return tree;
}
// If the key to be deleted is smaller than the root's key,
// then it lies in left subtree
if ( compare(key,root) < 0 )
set_left(root, avl_delete_node(get_left(root), key, get_left, set_left, get_right, set_right, get_height, set_height, compare, set_data));
const int comp = compare(root->data, data);
if (comp < 0)
{
root->right = _insert(root->right, data, compare, root);
}
else if (comp == 0)
return root;
else
root->left = _insert(root->left, data, compare, root);
// If the key to be deleted is greater than the root's key,
// then it lies in right subtree
else if(compare(key,root) > 0)
set_right(root, avl_delete_node(get_right(root), key, get_left, set_left, get_right, set_right, get_height, set_height, compare, set_data));
root->height = MAX(_get_height(root->left), _get_height(root->right)) + 1;
// if key is same as root's key, then This is the node
// to be deleted
return _balance_node(root);
}
// implementation
void *avl_read(avl_tree *root)
{
if (root == NULL)
return NULL;
return root->data;
}
avl_tree *avl_next(avl_tree *root)
{
if (root == NULL)
return NULL;
if (root->right != NULL)
{
root = root->right;
while (root->left != NULL)
{
root = root->left;
}
return root;
}
else
{
while (root->parent != NULL)
{
if (root->parent->left == root)
{
return root->parent;
}
root = root->parent;
}
return NULL;
}
}
avl_tree *avl_prev(avl_tree *root)
{
if (root == NULL)
return NULL;
if (root->left != NULL)
{
root = root->left;
while (root->right != NULL)
{
root = root->right;
}
return root;
}
else
{
while (root->parent != NULL)
{
if (root->parent->right == root)
{
return root->parent;
}
root = root->parent;
}
return NULL;
}
}
avl_tree *avl_insert(avl_tree *root, void *data, int (*compare)(void *, void *))
{
return _insert(root, data, compare, NULL);
}
avl_tree *avl_search(avl_tree *root, void *data, int(*compare)(void *, void *))
{
if(root == NULL)
return NULL;
const int comp = compare(root->data, data);
if (comp < 0)
{
return avl_search(root->right, data, compare);
}
else if (comp == 0)
return root;
else
return avl_search(root->left, data, compare);
}
avl_tree *avl_create()
{
return NULL;
}
avl_tree *avl_smallest(avl_tree *root)
{
if (root == NULL)
return NULL;
while (root->left != NULL)
root = root->left;
return root;
}
avl_tree *avl_largest(avl_tree *root)
{
if (root == NULL)
return NULL;
while (root->right != NULL)
root = root->right;
return root;
}
int avl_size(avl_tree *avl_tree)
{
if (avl_tree == NULL)
return 0;
return avl_size(avl_tree->left) + avl_size(avl_tree->right) + 1;
}
void avl_free(avl_tree *root, void (*delete_data)(void*))
{
if (root == NULL)
return;
avl_free(root->left, delete_data);
avl_free(root->right, delete_data);
if(delete_data != NULL)
delete_data(root->data);
free(root);
return;
}
avl_tree* avl_delete(avl_tree* root, void* data, int (*compare)(void*,void*))
{
if (root == NULL)
return NULL;
const int comp = compare(root->data, data);
if (comp < 0)
root->right = avl_delete(root->right, data, compare);
else if(comp > 0)
root->left = avl_delete(root->left, data, compare);
else
{
// node with only one child or no child
if( (get_left(root) == NULL) || (get_right(root) == NULL) )
if( (root->left == NULL) || (root->right == NULL) )
{
void *temp = get_left(root) != NULL ? get_left(root) : get_right(root);
avl_tree *child = root->left != NULL ? root->left : root->right;
// No child case
if(temp == NULL)
{
temp = root;
if(child == NULL)
{ // 0 child
free(root);
root = NULL;
}
else // One child case
else // 1 child
{
set_height(root,_get_height(temp,get_height));
set_left(root, get_left(temp));
set_right(root,get_right(temp));
set_data(root, temp);
//copy content of temp to root except for the parent
root->left = child->left;
root->right = child->right;
root->data = child->data;
root->height = child->height;
free(child);
}
//free(temp);
}
else
{
// node with two children: Get the inorder successor (smallest
// in the right subtree)
void* temp = get_right(root);
while(get_left(temp) != NULL)
temp = get_left(temp);
avl_tree* temp = root->right;
while(temp->left != NULL)
temp = temp->left;
// Copy the inorder successor's data to this node
set_data(root, temp);
root->data = temp->data;
// Delete the inorder successor
set_right(root, avl_delete_node(get_right(root), temp, get_left, set_left, get_right, set_right, get_height, set_height, compare, set_data));
root->right = avl_delete(root->right, temp->data, compare);
}
}
// If the tree had only one node then return
if (root == NULL)
return root;
// STEP 2: UPDATE HEIGHT OF THE CURRENT NODE
set_height(root, _max(_get_height(get_left(root),get_height), _get_height(get_right(root),get_height)) + 1);
// STEP 3: GET THE BALANCE FACTOR OF THIS NODE (to check whether
// this node became unbalanced)
int64_t balance = _get_balance_factor(root,get_left,get_right,get_height);
// If this node becomes unbalanced, then there are 4 cases
// Left Left Case
if (balance > 1 && _get_balance_factor(get_left(root),get_left,get_right,get_height) >= 0)
return _right_rotate(root,get_left,set_left,get_right,set_right,get_height,set_height);
// Left Right Case
if (balance > 1 && _get_balance_factor(get_left(root),get_left,get_right,get_height) < 0)
{
set_left(root,_left_rotate(get_left(root),get_left,set_left,get_right,set_right,get_height,set_height));
return _right_rotate(root,get_left,set_left,get_right,set_right,get_height,set_height);
}
// Right Right Case
if (balance < -1 && _get_balance_factor(get_right(root),get_left,get_right,get_height) <= 0)
return _left_rotate(root,get_left,set_left,get_right,set_right,get_height,set_height);
// Right Left Case
if (balance < -1 && _get_balance_factor(get_right(root),get_left,get_right,get_height) > 0)
{
set_right(root, _right_rotate(get_right(root),get_left,set_left,get_right,set_right,get_height,set_height));
return _left_rotate(root,get_left,set_left,get_right,set_right,get_height,set_height);
}
root->height = MAX(_get_height(root->left), _get_height(root->right)) + 1;
root = _balance_node(root);
return root;
}
// TESTS
int avl_test_calculate_height(avl_tree *avl_tree)
{
if (avl_tree == NULL)
return -1;
return MAX(avl_test_calculate_height(avl_tree->left), avl_test_calculate_height(avl_tree->right)) + 1;
}
int avl_test(avl_tree *avl_tree)
{
if (avl_tree == NULL)
return 1;
if (_balance_factor(avl_tree) < -1 || _balance_factor(avl_tree) > 1 || avl_test_calculate_height(avl_tree) != avl_tree->height)
return 0;
return avl_test(avl_tree->left) && avl_test(avl_tree->right);
}

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#ifndef _AVL_TREE_H_
#define _AVL_TREE_H_
#include <stdint.h>
#include "kdef.h"
void*NATIVE64 avl_insert_node(void *node, void *key,
void *(*get_left)(void *),
void (*set_left)(void *, void *),
void *(*get_right)(void *),
void(*set_right)(void *, void *),
int64_t (*get_height)(void *),
void(*set_height)(void *, int64_t),
int (*compare)(void *, void *));
void*NATIVE64 avl_delete_node(void *root, void *key,
void *(*get_left)(void *),
void (*set_left)(void *, void *),
void *(*get_right)(void *),
void(*set_right)(void *, void *),
int64_t (*get_height)(void *),
void(*set_height)(void *, int64_t),
int (*compare)(void *, void *),
void (*set_data)(void *, void *));
typedef struct __attribute__((packed)) _avl_tree
{
struct _avl_tree * left;
struct _avl_tree * right;
struct _avl_tree * parent;
int height;
void *data;
} avl_tree;
int avl_test(avl_tree* avl_tree);
int avl_test_calculate_height(avl_tree *avl_tree);
avl_tree* avl_smallest(avl_tree* root);
avl_tree* avl_largest(avl_tree* root);
avl_tree* avl_next(avl_tree* root);
avl_tree* avl_prev(avl_tree* root);
int avl_size(avl_tree* root);
void* avl_read(avl_tree *root);
avl_tree* avl_search(avl_tree* root, void* data, int(*compare)(void*,void*));
avl_tree* avl_create();
avl_tree* avl_insert(avl_tree* root, void* data, int(*compare)(void*,void*));
avl_tree* avl_delete(avl_tree* root, void* data, int(*compare)(void*,void*));
void avl_free(avl_tree *root, void (*delete_data)(void*));
#endif