From 60393e9404cf45009fc6533f896a32c23ac95316 Mon Sep 17 00:00:00 2001
From: sh <475784041@qq.com>
Date: Wed, 20 Mar 2019 21:16:17 +0800
Subject: [PATCH] Fix Bug in AVL Tree rorateLeftLeft and rotateRightRight
---
src/data-structures/tree/avl-tree/AvlTree.js | 12 ++++++++++--
.../tree/avl-tree/__test__/AvlTRee.test.js | 17 +++++++++++++++++
2 files changed, 27 insertions(+), 2 deletions(-)
diff --git a/src/data-structures/tree/avl-tree/AvlTree.js b/src/data-structures/tree/avl-tree/AvlTree.js
index 8a8b5d12cd..dee48b49e6 100644
--- a/src/data-structures/tree/avl-tree/AvlTree.js
+++ b/src/data-structures/tree/avl-tree/AvlTree.js
@@ -64,7 +64,11 @@ export default class AvlTree extends BinarySearchTree {
// Make left node to be a child of rootNode's parent.
if (rootNode.parent) {
- rootNode.parent.setLeft(leftNode);
+ if (rootNode.parent.left === rootNode) {
+ rootNode.parent.setLeft(leftNode);
+ } else {
+ rootNode.parent.setRight(leftNode);
+ }
} else if (rootNode === this.root) {
// If root node is root then make left node to be a new root.
this.root = leftNode;
@@ -145,7 +149,11 @@ export default class AvlTree extends BinarySearchTree {
// Make right node to be a child of rootNode's parent.
if (rootNode.parent) {
- rootNode.parent.setRight(rightNode);
+ if (rootNode.parent.left === rootNode) {
+ rootNode.parent.setLeft(rightNode);
+ } else {
+ rootNode.parent.setRight(rightNode);
+ }
} else if (rootNode === this.root) {
// If root node is root then make right node to be a new root.
this.root = rightNode;
diff --git a/src/data-structures/tree/avl-tree/__test__/AvlTRee.test.js b/src/data-structures/tree/avl-tree/__test__/AvlTRee.test.js
index cf64420091..7005558ff6 100644
--- a/src/data-structures/tree/avl-tree/__test__/AvlTRee.test.js
+++ b/src/data-structures/tree/avl-tree/__test__/AvlTRee.test.js
@@ -230,6 +230,23 @@ describe('AvlTree', () => {
expect(tree.root.height).toBe(3);
});
+ it('should do right right rotation and keeping left node safe', () => {
+ const tree = new AvlTree();
+ tree.insert(24);
+ tree.insert(12);
+ tree.insert(34);
+ tree.insert(15);
+
+ expect(tree.toString()).toBe('12,15,24,34');
+
+ tree.insert(18);
+ expect(tree.toString()).toBe('12,15,18,24,34');
+ expect(tree.root.height).toBe(2);
+ expect(tree.root.left.value).toBe(15);
+ expect(tree.root.left.left.value).toBe(12);
+ expect(tree.root.left.right.value).toBe(18);
+ });
+
it('should remove values from the tree with right-right rotation', () => {
const tree = new AvlTree();