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Commit 9bcf16b

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refactor: RotateListRight.js and added tests (#1101)
* Refactored RotatedListRight.js and added its tests * rotateListRight test and improved implementation * Review changes on constructor's loop
1 parent d05bbf7 commit 9bcf16b

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3 files changed

+59
-47
lines changed

3 files changed

+59
-47
lines changed

‎Data-Structures/Linked-List/RotateListRight.js

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This file was deleted.

‎Data-Structures/Linked-List/SinglyLinkedList.js

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@@ -6,7 +6,7 @@
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* a singly linked list.
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*/
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// Methods - size, head, addLast, addFirst, addAt, removeFirst, removeLast, remove, removeAt, indexOf, isEmpty, elementAt, findMiddle, get, clean
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// Methods - size, head, addLast, addFirst, addAt, removeFirst, removeLast, remove, removeAt, indexOf, isEmpty, elementAt, findMiddle, get, clean, rotateListRight
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class Node {
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constructor (data) {
@@ -16,9 +16,15 @@ class Node {
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}
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class LinkedList {
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constructor () {
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constructor (listOfValues) {
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this.headNode = null
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this.length = 0
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if (listOfValues instanceof Array) {
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for (const value of listOfValues) {
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this.addLast(value)
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}
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}
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}
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// initiates the currentNode and currentIndex and return as an object
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return list
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}
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// Method for Rotating a List to the right by k places
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rotateListRight (k) {
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let i = 0
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let current = this.headNode
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while (current) {
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i++
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current = current.next
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}
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k %= i
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current = this.headNode
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let prev = null
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while (k--) {
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if (!current || !current.next) {
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return current
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} else {
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while (current.next) {
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prev = current
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current = current.next
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}
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prev.next = current.next
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current.next = this.headNode
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this.headNode = current
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}
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}
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}
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// Method to iterate over the LinkedList
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iterator () {
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let { currentNode } = this.initiateNodeAndIndex()

‎Data-Structures/Linked-List/test/SinglyLinkedList.test.js

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@@ -222,4 +222,29 @@ describe('SinglyLinkedList', () => {
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list.clean()
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expect(list.isEmpty()).toBe(true)
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})
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it('should shift every node by k steps towards right, shifts tail nodes towards the start and change head of the list', () => {
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// Case 0: When head of list is null
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const tempNode = new LinkedList()
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expect(tempNode.get()).toEqual([])
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// Creating list
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const headNode = new LinkedList([10, 20, 30, 40, 50])
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// Case 1: when k = 0 => List should be unaffected
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headNode.rotateListRight(0)
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expect(headNode.get()).toEqual([10, 20, 30, 40, 50])
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// Case 2: Rotate right by 2 steps
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headNode.rotateListRight(2)
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expect(headNode.get()).toEqual([40, 50, 10, 20, 30])
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// Case 3: Rotate right by 12 steps
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headNode.rotateListRight(12)
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expect(headNode.get()).toEqual([20, 30, 40, 50, 10])
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// Case 4: when k = length of the list = 5 => List should be unaffected
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headNode.rotateListRight(5)
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expect(headNode.get()).toEqual([20, 30, 40, 50, 10])
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})
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})

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