feat: add Linked Queue

[co-bby]

*added linkedlist Queue implementation

*added a test to the implementation( I used the tests from array queue implementation but tweak to make the tests uniform on the site)

*updated the Directory.md

[appgurueu]

The implementation looks good! A couple things:

• The tests are practically identical (if not, they should be, since both queues should implement the same implicit "interface"). Please avoid duplicating them. Can you try:
  1. Adding a Queue Interface
  2. Parameterizing the tests for this interface in terms of the Queue implementation
  3. De-duplicating the Queue tests using this parameterized version
• Terminology-wise nitpick: I'd just call this a LinkedQueue. LinkedlistQueue violates CamelCase, and LinkedListQueue seems odd (is it a linked list, a queue, or both?).
• Formatting-wise, please check your comments for typos and grammar mistakes. Many are also missing a space after the //; the comments at the start are pretty oddly formatted, please clean them up using JSDoc.

[co-bby]

The implementation looks good! A couple things:

* The tests are practically identical (if not, they should be, since both queues should implement the same implicit "interface"). Please avoid duplicating them. Can you try:
  
  1. Adding a `Queue` Interface
  2. Parameterizing the tests for this interface in terms of the Queue implementation
  3. De-duplicating the `Queue` tests using this parameterized version

* Terminology-wise nitpick: I'd just call this a `LinkedQueue`. `LinkedlistQueue` violates CamelCase, and `LinkedListQueue` seems odd (is it a linked list, a queue, or both?).

* Formatting-wise, please check your comments for typos and grammar mistakes. Many are also missing a space after the `//`; the comments at the start are pretty oddly formatted, please clean them up using JSDoc.

thanks for the feedback. Working on that!

[co-bby]

The implementation looks good! A couple things:

* The tests are practically identical (if not, they should be, since both queues should implement the same implicit "interface"). Please avoid duplicating them. Can you try:
  
  1. Adding a `Queue` Interface
  2. Parameterizing the tests for this interface in terms of the Queue implementation
  3. De-duplicating the `Queue` tests using this parameterized version

* Terminology-wise nitpick: I'd just call this a `LinkedQueue`. `LinkedlistQueue` violates CamelCase, and `LinkedListQueue` seems odd (is it a linked list, a queue, or both?).

* Formatting-wise, please check your comments for typos and grammar mistakes. Many are also missing a space after the `//`; the comments at the start are pretty oddly formatted, please clean them up using JSDoc.

did you mean I should not duplicate the Queue test? if yes I don't think it will be possible since they have different names.

[appgurueu]

did you mean I should not duplicate the Queue test? if yes I don't think it will be possible since they have different names.

It is tricky but definitely possible. Here's a simple example for a fictive generic "Box" container type:

interface Box<T> {
	peek(): T
}

// These two classes are deliberately identical.

class BoxA<T> implements Box<T> {
	content: T
	constructor(content: T) {
		this.content = content
	}
	peek(): T {
		return this.content
	}
}

class BoxB<T> implements Box<T> {
	content: T
	constructor(content: T) {
		this.content = content
	}
	peek(): T {
		return this.content
	}
}

// Test function parameterized in terms of the class

type BoxConstructor = new<T>(content: T) => Box<T>

function test(Box: BoxConstructor) {
	const content = 42
	const c = new Box<number>(content)
	// This is just for a simple example that works in `ts-node`;
        // you'd instead use Jest's `expect(...).toBe(...)` here.
	if (c.peek() != content)
		throw new Error("test failed")
}

test(BoxA)
test(BoxB)

In terms of files, I'd like it split up as follows:

• queue.ts for the interface;
• array_queue.ts for the array implementation;
• linked_queue.ts for the linked implementation;

Ideally, the tests would have the same structure:

• test/queue.ts for the parameterized test (test function in the above example), which is exported;
• test/array_queue.ts as a simple one-liner calling the parameterized test for the imported array queue;
• test/linked_queue.ts analogeously as a one-liner calling the test for the imported linked queue

[appgurueu]

This seems to be going in the right direction. Please don't duplicate the Queue interface, but rather export it from a queue.ts file which both implementations import.

[co-bby]

This seems to be going in the right direction. Please don't duplicate the Queue interface, but rather export it from a queue.ts file which both implementations import.

is everything ok now?

[appgurueu]

This seems to be going in the right direction. Please don't duplicate the Queue interface, but rather export it from a queue.ts file which both implementations import.

is everything ok now?

Not quite: The tests still need to be deduplicated as I have described.

[co-bby]

This seems to be going in the right direction. Please don't duplicate the Queue interface, but rather export it from a queue.ts file which both implementations import.

is everything ok now?

Not quite: The tests still need to be deduplicated as I have described.

can you please check this out

[appgurueu]

Looking good! Only minor things left:

• Please lowercase Queue.test.ts to queue.test.ts to follow our naming conventions;
• Please remove leaading and trailing newlines

[co-bby]

* Please remove leaading and trailing newlines

Looking good! Only minor things left:

* Please lowercase `Queue.test.ts` to `queue.test.ts` to follow our naming conventions;

* Please remove leaading and trailing newlines

I'm confused with the leading and trailing newlines can you please show me an example?

[appgurueu]

Thank you for your contribution!

[co-bby]

Thank you for your contribution!

You are welcome! I have learnt a lot from you