From ef2be071b09617df3f4354920d99d17dc9561feb Mon Sep 17 00:00:00 2001
From: Ritik2604 <49342895+Ritik2604@users.noreply.github.com>
Date: Sat, 23 May 2020 05:33:40 +0530
Subject: [PATCH] Create AVLSimple

---
 DataStructures/Trees/AVLSimple | 106 +++++++++++++++++++++++++++++++++
 1 file changed, 106 insertions(+)
 create mode 100644 DataStructures/Trees/AVLSimple

diff --git a/DataStructures/Trees/AVLSimple b/DataStructures/Trees/AVLSimple
new file mode 100644
index 000000000..1f2c2bd6a
--- /dev/null
+++ b/DataStructures/Trees/AVLSimple
@@ -0,0 +1,106 @@
+public class AVLTree {
+	private class Node{
+		int data;
+		int height;
+		Node left;
+		Node right;
+		Node(int data){
+			this.data=data;
+			this.height=1;
+		}
+		
+	}
+	private Node root;
+	public void insert(int data) {
+		this.root=insert(this.root,data);
+	}
+	private Node insert(Node node,int item) {
+		if(node==null) {
+			Node add=new Node(item);
+			return add;
+		}
+		if(node.data>item) {
+			node.left=insert(node.left,item);
+		}
+		if(node.data<item) {
+			node.right=insert(node.right,item);
+		}
+		node.height=Math.max(height(node.left),height(node.right))+1;
+		int bf=bf(node);
+		//LL case
+		if(bf>1&&item<node.left.data)
+			return rightRotate(node);
+		//RR case
+		if(bf<-1&&item>node.right.data)
+			return leftRotate(node);
+		//RL case
+		if(bf<-1&&item<node.right.data) {
+			node.right=rightRotate(node.right);
+			return leftRotate(node);
+		}
+		//LR case
+		if(bf>1&&item>node.left.data) {
+			node.left=leftRotate(node.left);
+			return rightRotate(node);
+		}
+			
+		return node;
+	}
+	public void display() { 
+		this.display(this.root);
+		System.out.println(this.root.height);
+	}
+	private void display (Node node) {
+		String str="";
+		if(node.left!=null)
+			str+=node.left.data+"=>";
+		else
+			str+="END=>";
+		str+=node.data+"";
+		if(node.right!=null)
+			str+="<="+node.right.data;
+		else
+			str+="<=END";
+		System.out.println(str);
+		if(node.left!=null)
+			display(node.left);
+		if(node.right!=null)
+			display(node.right);
+	}
+	private int height(Node node) {
+		if(node==null) {
+			return 0;
+		}
+		return node.height;
+		
+	}
+	private int bf(Node node) {
+		if(node==null)
+			return 0;
+		return height(node.left)-height(node.right);
+	}
+	
+	private Node rightRotate(Node c) {
+		Node b=c.left;
+		Node T3=b.right;
+		
+		b.right=c;
+		c.left=T3;
+		c.height=Math.max(height(c.left),height(c.right))+1;
+		b.height=Math.max(height(b.left),height(b.right))+1;
+		return b;
+		
+	}
+	private Node leftRotate(Node c) {
+		Node b=c.right;
+		Node T3=b.left;
+		
+		b.left=c;
+		c.right=T3;
+		c.height=Math.max(height(c.left),height(c.right))+1;
+		b.height=Math.max(height(b.left),height(b.right))+1;
+		return b;
+		
+	}
+
+}