avl tree c++

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2

#include <stdio.h>
#include "avltree.h"
/*
    remove all nodes of an AVL tree
*/
void dispose(node* t)
{
    if( t != NULL )
    {
        dispose( t->left );
        dispose( t->right );
        free( t );
    }
}

/*
    find a specific node's key in the tree
*/
node* find(int e, node* t )
{
    if( t == NULL )
        return NULL;
    if( e < t->data )
        return find( e, t->left );
    else if( e > t->data )
        return find( e, t->right );
    else
        return t;
}

/*
    find minimum node's key
*/
node* find_min( node* t )
{
    if( t == NULL )
        return NULL;
    else if( t->left == NULL )
        return t;
    else
        return find_min( t->left );
}

/*
    find maximum node's key
*/
node* find_max( node* t )
{
    if( t != NULL )
        while( t->right != NULL )
            t = t->right;

    return t;
}

/*
    get the height of a node
*/
static int height( node* n )
{
    if( n == NULL )
        return -1;
    else
        return n->height;
}

/*
    get maximum value of two integers
*/
static int max( int l, int r)
{
    return l > r ? l: r;
}

/*
    perform a rotation between a k2 node and its left child

    note: call single_rotate_with_left only if k2 node has a left child
*/

static node* single_rotate_with_left( node* k2 )
{
    node* k1 = NULL;

    k1 = k2->left;
    k2->left = k1->right;
    k1->right = k2;

    k2->height = max( height( k2->left ), height( k2->right ) ) + 1;
    k1->height = max( height( k1->left ), k2->height ) + 1;
    return k1; /* new root */
}

/*
    perform a rotation between a node (k1) and its right child

    note: call single_rotate_with_right only if
    the k1 node has a right child
*/

static node* single_rotate_with_right( node* k1 )
{
    node* k2;

    k2 = k1->right;
    k1->right = k2->left;
    k2->left = k1;

    k1->height = max( height( k1->left ), height( k1->right ) ) + 1;
    k2->height = max( height( k2->right ), k1->height ) + 1;

    return k2;  /* New root */
}

/*

    perform the left-right double rotation,

    note: call double_rotate_with_left only if k3 node has
    a left child and k3's left child has a right child
*/

static node* double_rotate_with_left( node* k3 )
{
    /* Rotate between k1 and k2 */
    k3->left = single_rotate_with_right( k3->left );

    /* Rotate between K3 and k2 */
    return single_rotate_with_left( k3 );
}

/*
    perform the right-left double rotation

   notes: call double_rotate_with_right only if k1 has a
   right child and k1's right child has a left child
*/



static node* double_rotate_with_right( node* k1 )
{
    /* rotate between K3 and k2 */
    k1->right = single_rotate_with_left( k1->right );

    /* rotate between k1 and k2 */
    return single_rotate_with_right( k1 );
}

/*
    insert a new node into the tree
*/
node* insert(int e, node* t )
{
    if( t == NULL )
    {
        /* Create and return a one-node tree */
        t = (node*)malloc(sizeof(node));
        if( t == NULL )
        {
            fprintf (stderr, "Out of memory!!! (insert)\n");
            exit(1);
        }
        else
        {
            t->data = e;
            t->height = 0;
            t->left = t->right = NULL;
        }
    }
    else if( e < t->data )
    {
        t->left = insert( e, t->left );
        if( height( t->left ) - height( t->right ) == 2 )
            if( e < t->left->data )
                t = single_rotate_with_left( t );
            else
                t = double_rotate_with_left( t );
    }
    else if( e > t->data )
    {
        t->right = insert( e, t->right );
        if( height( t->right ) - height( t->left ) == 2 )
            if( e > t->right->data )
                t = single_rotate_with_right( t );
            else
                t = double_rotate_with_right( t );
    }
    /* Else X is in the tree already; we'll do nothing */

    t->height = max( height( t->left ), height( t->right ) ) + 1;
    return t;
}

/*
    remove a node in the tree
*/
node* delete( int e, node* t )
{
    printf( "Sorry; Delete is unimplemented; %d remains\n", e );
    return t;
}

/*
    data data of a node
*/
int get(node* n)
{
    return n->data;
}

/*
    Recursively display AVL tree or subtree
*/
void display_avl(node* t)
{
    if (t == NULL)
        return;
    printf("%d",t->data);

    if(t->left != NULL)
        printf("(L:%d)",t->left->data);
    if(t->right != NULL)
        printf("(R:%d)",t->right->data);
    printf("\n");

    display_avl(t->left);
    display_avl(t->right);
}
Code language: C++ (cpp)

Popularity 10/10 Helpfulness 1/10 Language cpp

Source: www.learnc.net

Tags: avl-tree c++

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Contributed on Dec 22 2021

Vast Vicuña

0 Answers Avg Quality 2/10

avl tree

Comment

1

z                               z                           x
    / \                            /   \                        /  \ 
   y   T4  Left Rotate (y)        x    T4  Right Rotate(z)    y      z
  / \      - - - - - - - - ->    /  \      - - - - - - - ->  / \    / \
T1   x                          y    T3                    T1  T2 T3  T4
    / \                        / \
  T2   T3                    T1   T2

Popularity 10/10 Helpfulness 1/10 Language whatever

Source: www.geeksforgeeks.org

Tags: avl-tree avl-tre

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Contributed on May 04 2022

Nethmi Mohotti

0 Answers Avg Quality 2/10

avl tree c++

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0

Popularity 1/10 Helpfulness 1/10 Language cpp

Source: Grepper

Tags: avl-tree c++

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Contributed on Nov 22 2021

Ashamed Ape

0 Answers Avg Quality 2/10

Avl Tree

Comment

-2

class treeNode(object):
	def __init__(self, value):
		self.value = value
		self.l = None
		self.r = None
		self.h = 1

class AVLTree(object):

	def insert(self, root, key):
	
		if not root:
			return treeNode(key)
		elif key < root.value:
			root.l = self.insert(root.l, key)
		else:
			root.r = self.insert(root.r, key)

		root.h = 1 + max(self.getHeight(root.l),
						self.getHeight(root.r))

		b = self.getBal(root)

		if b > 1 and key < root.l.value:
			return self.rRotate(root)

		if b < -1 and key > root.r.value:
			return self.lRotate(root)

		if b > 1 and key > root.l.value:
			root.l = self.lRotate(root.l)
			return self.rRotate(root)

		if b < -1 and key < root.r.value:
			root.r = self.rRotate(root.r)
			return self.lRotate(root)

		return root

	def lRotate(self, z):

		y = z.r
		T2 = y.l

		y.l = z
		z.r = T2

		z.h = 1 + max(self.getHeight(z.l),
						self.getHeight(z.r))
		y.h = 1 + max(self.getHeight(y.l),
						self.getHeight(y.r))

		return y

	def rRotate(self, z):

		y = z.l
		T3 = y.r

		y.r = z
		z.l = T3

		z.h = 1 + max(self.getHeight(z.l),
						self.getHeight(z.r))
		y.h = 1 + max(self.getHeight(y.l),
						self.getHeight(y.r))

		return y

	def getHeight(self, root):
		if not root:
			return 0

		return root.h

	def getBal(self, root):
		if not root:
			return 0

		return self.getHeight(root.l) - self.getHeight(root.r)

	def preOrder(self, root):

		if not root:
			return

		print("{0} ".format(root.value), end="")
		self.preOrder(root.l)
		self.preOrder(root.r)

Tree = AVLTree()
root = None

root = Tree.insert(root, 1)
root = Tree.insert(root, 2)
root = Tree.insert(root, 3)
root = Tree.insert(root, 4)
root = Tree.insert(root, 5)
root = Tree.insert(root, 6)

# Preorder Traversal
print("Preorder traversal of the",
	"constructed AVL tree is")
Tree.preOrder(root)
print()

Popularity 10/10 Helpfulness 1/10 Language python

Source: favtutor.com

Tags: avl-tree avl-tre

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Contributed on Oct 04 2021

Itchy Impala

0 Answers Avg Quality 2/10

avl tree

Comment

0

z                               z                           x
    / \                            /   \                        /  \ 
   y   T4  Left Rotate (y)        x    T4  Right Rotate(z)    y      z
  / \      - - - - - - - - ->    /  \      - - - - - - - ->  / \    / \
T1   x                          y    T3                    T1  T2 T3  T4
    / \                        / \
  T2   T3                    T1   T2

Popularity 10/10 Helpfulness 1/10 Language whatever

Source: www.geeksforgeeks.org

Tags: avl-tree avl-tre

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Contributed on May 04 2022

Nethmi Mohotti

0 Answers Avg Quality 2/10

avl tree c++

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