AVL Tree Added

Author: nisabmohd

build/classes/Trees/AVL$AVLNode.class

@@ -0,0 +1,109 @@
+package Trees;
+
+import java.util.*;
+
+public class AVL {
+
+    private class AVLNode {
+
+        int val;
+        int height;
+        AVLNode left, right;
+
+        public AVLNode(int val) {
+            this.val = val;
+            this.height = 1;
+        }
+
+    }
+    private AVLNode root;
+
+    public void add(int val) {
+        root = add(val, root);
+    }
+
+    private int getHeight(AVLNode node) {
+        return node == null ? 0 : node.height;
+    }
+
+    private int getBalanceFactor(AVLNode node) {
+        if (node == null) {
+            return 0;
+        }
+        return getHeight(node.left) - getHeight(node.left);
+    }
+
+    private AVLNode add(int val, AVLNode root) {
+        if (root == null) {
+            return new AVLNode(val);
+        } else if (root.val > val) {
+            root.left = add(val, root.left);
+        } else if (root.val < val) {
+            root.right = add(val, root.right);
+        } else {
+            return root;
+        }
+        root.height = 1 + Math.max(getHeight(root.left), getHeight(root.right));
+        int balanceFactor = getBalanceFactor(root);
+        // Left  Left Rotation
+        if (balanceFactor > 1 && root.left.val > val) {
+            root = leftRotate(root);
+        }
+        // Right  Right Rotation
+        if (balanceFactor < -1 && root.right.val < val) {
+            root = rightRotate(root);
+        }
+        // Left  Right Rotation
+        if (balanceFactor > 1 && root.left.val < val) {
+            root.left = leftRotate(root.left);
+            root = rightRotate(root);
+        }
+        // Right  Left Rotation
+        if (balanceFactor < -1 && root.right.val > val) {
+            root.right = rightRotate(root.right);
+            root = leftRotate(root);
+        }
+        return root;
+    }
+
+    private AVLNode leftRotate(AVLNode node) {
+        AVLNode temp = node.right;
+        AVLNode x = temp.left;
+        temp.left = node;
+        node.right = x;
+        temp.height = 1 + Math.max(getHeight(temp.left), getHeight(temp.right));
+        node.height = 1 + Math.max(getHeight(node.left), getHeight(node.right));
+        return temp;
+    }
+
+    private AVLNode rightRotate(AVLNode node) {
+        AVLNode temp = node.left;
+        AVLNode y = temp.right;
+        temp.right = node;
+        node.left = y;
+        temp.height = 1 + Math.max(getHeight(temp.left), getHeight(temp.right));
+        node.height = 1 + Math.max(getHeight(node.left), getHeight(node.right));
+        return temp;
+    }
+
+    public List<Object> inOrder() {
+        return inOrder(root);
+    }
+
+    private List<Object> inOrder(AVLNode node) {
+        if (node == null) {
+            return new ArrayList<>();
+        }
+        List<Object> ans = new ArrayList<>();
+        ans.addAll(inOrder(node.left));
+        ans.add(node.val);
+        ans.addAll(inOrder(node.right));
+        return ans;
+    }
+
+    @Override
+    public String toString() {
+        return inOrder().toString();
+    }
+
+}

build/classes/Trees/AVL.class

@@ -5,7 +5,7 @@
 public class BinaryTree implements BTree {
 
     @Override
-    public List<Object> inOrder(TreeNode node) {
+    public  List<Object> inOrder(TreeNode node) {
         if (node == null) {
             return new ArrayList<>();
         }