-
Notifications
You must be signed in to change notification settings - Fork 4
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
refactor: core - switch from basic arrays to linked lists to improve …
…performance
- Loading branch information
Showing
5 changed files
with
224 additions
and
30 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,9 @@ | ||
| class Node { | ||
| constructor(value) { | ||
| this.value = value; | ||
| this.next = null; | ||
| this.prev = null; | ||
| } | ||
| } | ||
|
|
||
| module.exports = Node; |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,156 @@ | ||
| const Node = require('./Node'); | ||
|
|
||
| class Queue { | ||
| constructor() { | ||
| this.first = null; | ||
| this.last = null; | ||
| this.size = 0; | ||
| } | ||
|
|
||
| isEmpty() { | ||
| return !this.size; | ||
| } | ||
|
|
||
| enqueue(item) { | ||
| // Create node | ||
| const newNode = new Node(item); | ||
| /** | ||
| * * If our list is empty than both our | ||
| * * first item and last item is going to point the new node. | ||
| */ | ||
| if (this.isEmpty()) { | ||
| this.first = newNode; | ||
| this.last = newNode; | ||
| newNode.prev = null; | ||
| } else { | ||
| newNode.prev = this.last; | ||
|
|
||
| this.last.next = newNode; | ||
| this.last = newNode; | ||
| } | ||
| this.size += 1; | ||
| return this; | ||
| } | ||
| /** | ||
| * | ||
| * @returns | ||
| */ | ||
|
|
||
| dequeue() { | ||
| //* if our queue is empty we return null | ||
| if (this.isEmpty()) return null; | ||
| const itemToBeRemoved = this.first; | ||
| /** | ||
| * * if both our first and last node are pointing the same item | ||
| * * we dequeued our last node. | ||
| */ | ||
| if (this.first === this.last) { | ||
| this.last = null; | ||
| } | ||
| this.first = this.first.next; | ||
| this.size -= 1; | ||
| return itemToBeRemoved; | ||
| } | ||
|
|
||
| check() { | ||
| let current = this.first; | ||
| while (current) { | ||
| // while not null | ||
| current = current.next; | ||
| } | ||
| } | ||
|
|
||
| /** | ||
| * Searches inside list in linear fashion , | ||
| * Time complexity O(n) | ||
| * @param {*} item String , Number , Object | ||
| * @returns Node , null | ||
| */ | ||
| search(item) { | ||
| let current = this.first; | ||
| if (typeof item !== typeof current.value) { | ||
| return null; | ||
| } | ||
| while (current !== null) { | ||
| if (current.value === item) { | ||
| return current; | ||
| } | ||
| if (typeof item === 'object') { | ||
| const itemKeys = Object.keys(item); | ||
| for (let i = 0; i < itemKeys.length; i += 1) { | ||
| // check all item properties agains current.value properties | ||
| if ( | ||
| Object.prototype.hasOwnProperty.call( | ||
| current.value, | ||
| itemKeys[i] | ||
| ) | ||
| ) { | ||
| if (current.value[itemKeys[i]] === item[itemKeys[i]]) { | ||
| return current; | ||
| } | ||
| } | ||
| } | ||
| } | ||
| current = current.next; | ||
| } | ||
| return null; | ||
| } | ||
|
|
||
| bubbleSort() { | ||
| let { last } = this; | ||
| while (last) { | ||
| let node = this.first; | ||
| while (node !== last) { | ||
| const { next } = node; | ||
| if (typeof node.value === 'object') { | ||
| // object comparision in first matched (common) property | ||
| const itemKeys = Object.keys(node.value); | ||
| for (let i = 0; i < itemKeys.length; i += 1) { | ||
| if ( | ||
| Object.prototype.hasOwnProperty.call( | ||
| next.value, | ||
| itemKeys[i] | ||
| ) | ||
| ) { | ||
| if ( | ||
| node.value[itemKeys[i]] > | ||
| next.value[itemKeys[i]] | ||
| ) { | ||
| // swap | ||
| [node.value, next.value] = [ | ||
| next.value, | ||
| node.value, | ||
| ]; | ||
| break; | ||
| } | ||
| } | ||
| } | ||
| } else if (typeof node.value === 'number') { | ||
| if (node.value > next.value) { | ||
| // swap | ||
| [node.value, next.value] = [next.value, node.value]; | ||
| } | ||
| } else if (typeof node.value === 'string') { | ||
| // Not Implemented yet | ||
| } | ||
|
|
||
| node = next; | ||
| } | ||
| last = last.prev; // shorten the range that must be bubbled through | ||
| } | ||
| } | ||
|
|
||
| /** | ||
| * * Returns the next element to be dequeued. | ||
| * @returns | ||
| */ | ||
| peek() { | ||
| return this.first; | ||
| } | ||
|
|
||
| tail() { | ||
| return this.last; | ||
| } | ||
| } | ||
|
|
||
| module.exports = Queue; |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters