idati

A set of data structures and algorithms commonly used in front-end development.

Install

npm install idati
# or
yarn add idati

What's in it?

• Stack
• Queue
• PriorityQueue
• LRUCache

Collection (Interface)

methods

• clear() Removes all the elements from this collection.
• contains(e: E): boolean Returns true if this collection contains the specified element.
• isEmpty(): boolean Returns true if this collection contains no elements.
• size(): number Returns the number of elements in this collection.
• toArray(): T[] Returns an array containing all the elements in this collection.

Stack<E>

Order elements in a LIFO (last-in-first-out) manner.

Collection Symbol.iterator

Example

import {Stack} from 'idati';

const stack = new Stack();

stack.push(1);
stack.push(2);

stack.pop();  // 2
stack.pop();  // 1

Constructor

new Stack();
new Stack(['init', 'data']);

Methods

• push(e: E) Pushes an item onto the top of this stack.
• peek(): E Looks at the object at the top of this stack without removing it from the stack.
• pop(): E Retrieves and removes the top of this stack.

Queue<E>

Order elements in a FIFO (first-in-first-out) manner.

Collection Symbol.iterator

Example

import {Queue} from 'idati';

const queue = new Queue();

queue.offer(1);
queue.offer(2);

queue.poll();  // 1
queue.poll();  // 2

Constructor

new Queue();
new Queue(['init', 'data']);

Methods

• offer(e: E) Inserts the specified element into this queue.
• peek(): E Retrieves, but does not remove, the head of this queue.
• poll(): E Retrieves and removes the head of this queue.

PriorityQueue<E>

The elements of the priority queue are ordered according to the Comparator provided at queue construction time.

Collection Symbol.iterator

Example

import {PriorityQueue} from 'idati';

const queue = new PriorityQueue<{ value: number }>(
  (a, b) => b.value - a.value,
);

queue.offer({value: 3});
queue.offer({value: 5});
queue.offer({value: 1});

queue.poll();  // {value: 5}
queue.poll();  // {value: 3}
queue.poll();  // {value: 1}

Constructor

new PriorityQueue();
new PriorityQueue(initData);
new PriorityQueue(comparator);
new PriorityQueue(initData, comparator);

Methods

• offer(e: E) Inserts the specified element into this priority queue.
• peek(): E Retrieves, but does not remove, the head of this queue.
• poll(): E Retrieves and removes the head of this queue.

LRUCache<V, K>

A cache that holds a limited number of values, When a value is added to a full cache, that will delete the "least-recently-used" items.

Symbol.iterator

Example

import {LRUCache} from 'idati';

const cache = new LRUCache<number>(2);  // max size 2
cache.set('a', 1);
cache.set('b', 2);
cache.set('c', 3); // deletes 'a'
cache.get('a'); // undefined
cache.get('b');
cache.set('d', 4); // deletes 'c'
console.log(cache.get('c')); // undefined

Constructor

new cache(maxSize);

Methods

• set(key: K, value: V) Inserts entry into the cache and updates the " recently used".
• peek(key: K): V Retrieves the value for key from this cache.
• get(key: K): V Retrieves the value for key from this cache and updates the "recently used".
• remove(key: K) Removes the entry for key if it exists.
• clear() Removes all the entry in the cache.
• size() Returns the number of entries in the cache.
• toArray(): V[] Return an array of the values in the cache.