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Jul 18, 2021
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Original file line number Diff line number Diff line change
@@ -0,0 +1,256 @@
import Foundation

class RedBlackTreeNode<T: Comparable> {
var value: T
var isRed: Bool
var left: RedBlackTreeNode?
var right: RedBlackTreeNode?

init(value: T, isRed: Bool, left: RedBlackTreeNode?, right: RedBlackTreeNode?) {
self.value = value
self.isRed = isRed
self.left = left
self.right = right
}

static func isRedNode(node: RedBlackTreeNode?) -> Bool {
if (node == nil) {
return false
}
return node!.isRed
}

func clockwiseRotate() -> RedBlackTreeNode {
let t = self.left!
self.left = t.right
t.right = self
t.isRed = RedBlackTreeNode.isRedNode(node: t.right)
t.right!.isRed = true
return t
}

func counterclockwiseRotate() -> RedBlackTreeNode {
let t = self.right!
self.right = t.left
t.left = self
t.isRed = RedBlackTreeNode.isRedNode(node: t.left)
t.left!.isRed = true
return t
}

func flip() {
self.isRed = !self.isRed
}

func exchange() {
self.flip()
self.left?.flip()
self.right?.flip()
}

func minimum() -> RedBlackTreeNode {
if (self.left == nil) {
return self
}
return self.left!.minimum()
}

func maximum() -> RedBlackTreeNode {
if (self.right == nil) {
return self
}
return self.right!.maximum()
}

func bubbleUp() -> RedBlackTreeNode {
var t = self
if (RedBlackTreeNode.isRedNode(node: t.right)) {
t = t.counterclockwiseRotate()
}
if (RedBlackTreeNode.isRedNode(node: t.left) && RedBlackTreeNode.isRedNode(node: t.left!.left)) {
t = t.clockwiseRotate()
}
if (RedBlackTreeNode.isRedNode(node: t.left) && RedBlackTreeNode.isRedNode(node: t.right)) {
t.exchange()
}
return t
}

func alignLeftNode() -> RedBlackTreeNode {
var t = self
t.exchange()
if (self.right != nil && RedBlackTreeNode.isRedNode(node: t.right!.left)) {
t.right = t.right!.clockwiseRotate()
t = t.counterclockwiseRotate()
t.exchange()
}
return t
}

func alignRightNode() -> RedBlackTreeNode {
var t = self
t.exchange()
if (self.left != nil && RedBlackTreeNode.isRedNode(node: t.left!.left)) {
t = t.clockwiseRotate()
t.exchange()
}
return t
}

func search(value: T) -> RedBlackTreeNode? {
if (self.value == value) {
return self
} else if (self.value < value) {
return self.left?.search(value: value)
} else {
return self.right?.search(value: value)
}
}

func removeMinimum() -> RedBlackTreeNode? {
if (self.left == nil) {
return nil
}
var t = self
if (!RedBlackTreeNode.isRedNode(node: t.left) && !RedBlackTreeNode.isRedNode(node: t.left!.left)) {
t = t.alignLeftNode()
}
t.left = t.left!.removeMinimum()
return t.bubbleUp()
}

func preorderTraversal() -> Array<T> {
var traversal: Array<T> = [self.value]
if (self.left != nil) {
traversal += left!.inorderTraversal()
}
if (self.right != nil) {
traversal += right!.inorderTraversal()
}
return traversal;
}

func inorderTraversal() -> Array<T> {
var traversal: Array<T> = []
if (self.left != nil) {
traversal += left!.inorderTraversal()
}
traversal += [self.value]
if (self.right != nil) {
traversal += right!.inorderTraversal()
}
return traversal;
}

func postorderTraversal() -> Array<T> {
var traversal: Array<T> = []
if (self.left != nil) {
traversal += left!.inorderTraversal()
}
if (self.right != nil) {
traversal += right!.inorderTraversal()
}
traversal += [self.value]
return traversal;
}
}

class RedBlackTree<T: Comparable> {
var root: RedBlackTreeNode<T>? = nil

static func insert(inRoot: RedBlackTreeNode<T>?, val: T) -> RedBlackTreeNode<T>? {
var root = inRoot
if (root == nil) {
return RedBlackTreeNode(value: val, isRed: true, left: nil, right: nil)
}
if (RedBlackTreeNode.isRedNode(node: root!.left) && RedBlackTreeNode.isRedNode(node: root!.right)) {
root!.exchange()
}
if (val == root!.value) {
root!.value = val
} else if (val < root!.value) {
root!.left = insert(inRoot: root!.left, val: val)
} else {
root!.right = insert(inRoot: root!.right, val: val)
}
if (RedBlackTreeNode.isRedNode(node: root!.right)) {
root = root!.counterclockwiseRotate()
}
if (RedBlackTreeNode.isRedNode(node: root!.left) && RedBlackTreeNode.isRedNode(node: root!.left!.left)) {
root = root!.clockwiseRotate()
}
if (RedBlackTreeNode.isRedNode(node: root!.left) && RedBlackTreeNode.isRedNode(node: root!.right)) {
root!.exchange();
}
return root;
}

static func remove(inRoot: RedBlackTreeNode<T>?, val: T) -> RedBlackTreeNode<T>? {
var root = inRoot;
if (val < root!.value) {
if (root!.left != nil && !(RedBlackTreeNode.isRedNode(node: root!.left)) && !(RedBlackTreeNode.isRedNode(node: root!.left!.left))) {
root = root!.alignLeftNode()
}
root!.left = remove(inRoot: root!.left, val: val);
} else {
if (RedBlackTreeNode.isRedNode(node: root!.left)) {
root = root!.clockwiseRotate()
}
if (val == root!.value && root!.right == nil) {
return nil
}
if (root!.right != nil && !(RedBlackTreeNode.isRedNode(node: root!.right)) && !(RedBlackTreeNode.isRedNode(node: root!.right!.left))) {
root = root!.alignRightNode()
}
if (val == root!.value) {
root!.value = root!.right!.minimum().value
root!.right = root!.right!.removeMinimum()
} else {
root!.right = remove(inRoot: root!.right, val: val);
}
}
return root!.bubbleUp()
}

func insert(value: T) {
root = RedBlackTree.insert(inRoot: root, val: value)
if (root != nil) {
root!.isRed = false
}
}

func remove(value: T) {
if (search(value: value) == nil) {
return
}
root = RedBlackTree.remove(inRoot: root, val: value)
if (root != nil) {
root!.isRed = false
}
}

func search(value: T) -> RedBlackTreeNode<T>? {
return root?.search(value: value)
}

func preorderTraversal() -> Array<T> {
if (root == nil) {
return Array<T>()
}
return root!.preorderTraversal()
}

func inorderTraversal() -> Array<T> {
if (root == nil) {
return Array<T>()
}
return root!.inorderTraversal()
}

func postorderTraversal() -> Array<T> {
if (root == nil) {
return Array<T>()
}
return root!.postorderTraversal()
}
}

This file was deleted.

4 changes: 2 additions & 2 deletions README.md
Original file line number Diff line number Diff line change
@@ -1,9 +1,9 @@
# swift-algorithms-data-structs [![Awesome](https://cdn.rawgit.com/sindresorhus/awesome/d7305f38d29fed78fa85652e3a63e154dd8e8829/media/badge.svg)](https://github.com/sindresorhus/awesome)

[![Language](https://img.shields.io/badge/language-Swift_5.0-orange.svg)]()
[![Language](https://img.shields.io/badge/language-Swift_5.3-orange.svg)]()
[![License](https://img.shields.io/badge/license-MIT-blue.svg)]()

**Last Update: 27/April/2019.**
**Last Update: 18/July/2021.**

![](https://github.com/jVirus/swift-algorithms-data-structs/blob/master/cover-algo-datastruct.png)

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