Created
February 24, 2016 01:17
-
-
Save thmain/83d624eb2965255550c2 to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
public class AVLTree { | |
public int getBalance(Node n) { | |
if (n != null) { | |
return (getHeight(n.left) - getHeight(n.right)); | |
} | |
return 0; | |
} | |
public int getHeight(Node n) { | |
if (n != null) { | |
return n.height; | |
} | |
return 0; | |
} | |
public Node rightRotate(Node y) { | |
Node x = y.left; | |
Node T2 = x.right; | |
// Rotation | |
x.right = y; | |
y.left = T2; | |
// update their heights | |
x.height = Math.max(getHeight(x.left), getHeight(x.right)) + 1; | |
y.height = Math.max(getHeight(y.left), getHeight(y.right)) + 1; | |
return x; | |
} | |
public Node leftRotate(Node x) { | |
Node y = x.right; | |
Node T2 = y.left; | |
// Rotation | |
y.left = x; | |
x.right = T2; | |
// update their heights | |
x.height = Math.max(getHeight(x.left), getHeight(x.right)) + 1; | |
y.height = Math.max(getHeight(y.left), getHeight(y.right)) + 1; | |
return y; | |
} | |
public Node insert(Node node, int data) { | |
if (node == null) { | |
return (new Node(data)); | |
} | |
if (node.data > data) { | |
node.left = insert(node.left, data); | |
} else { | |
node.right = insert(node.right, data); | |
} | |
// update the node height | |
node.height = Math.max(getHeight(node.left), getHeight(node.right)) + 1; | |
int balDiff = getBalance(node); | |
// Left Rotate | |
if (balDiff > 1 && data < node.left.data) { | |
return rightRotate(node); | |
} | |
// Right Rotate | |
if (balDiff < -1 && data > node.right.data) { | |
return leftRotate(node); | |
} | |
// Left Right Rotate | |
if (balDiff > 1 && data > node.left.data) { | |
node.left = leftRotate(node.left); | |
return rightRotate(node); | |
} | |
// Right Left Rotate | |
if (balDiff < -1 && data < node.right.data) { | |
node.right = rightRotate(node.right); | |
return leftRotate(node); | |
} | |
return node; | |
} | |
public void inorder(Node root) { | |
if (root != null) { | |
inorder(root.left); | |
System.out.print(" " + root.data); | |
inorder(root.right); | |
} | |
} | |
public static void main(String args[]) { | |
Node root = null; | |
AVLTree i = new AVLTree(); | |
root = i.insert(root, 4); | |
root = i.insert(root, 2); | |
root = i.insert(root, 1); | |
root = i.insert(root, 5); | |
root = i.insert(root, 6); | |
root = i.insert(root, 9); | |
root = i.insert(root, 14); | |
root = i.insert(root, 11); | |
root = i.insert(root, 10); | |
root = i.insert(root, 20); | |
System.out.print("Inorder Traversal of Constructed AVL Tree :"); | |
i.inorder(root); | |
System.out.print("\n New Root of AVL Tree is : " + root.data); | |
} | |
} | |
class Node { | |
int data; | |
Node left; | |
Node right; | |
int height; | |
public Node(int data) { | |
this.data = data; | |
height = 1; | |
} | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment