studying/dataStructures/linkedList.js at master · naimahnash/studying · GitHub

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class LLNode{
  constructor(value){
    this.value = value;
    this.next = null;
  }
}

export class LinkedList{
  constructor(){
    this.head = null;
    this.size = 0;
  }

  add(value){
    let newNode = new LLNode(value);
    if(!this.head){
      this.head = newNode;
    }else{
      let node = this.head;
      while(node.next){
        node = node.next;
      }
      node.next = newNode;
    }
    this.size++;
  }

  isEmpty(){
    return this.size === 0;
  }
}

class DLLNode{
  constructor(value){
    this.value = value;
    this.next = null;
    this.prev = null;
  }
}

export class DoubleLinkedList{
  constructor(){
    this.head = null;
    this.size = 0;
  }

  add(value){
    let newNode = new DLLNode(value), prevNode = null;
    if(!this.head){
      this.head = newNode;
    }else{
      let node = this.head;
      while(node.next){
        prevNode = node;
        node = node.next;
      }
      node.next = newNode;
      node.prev = prevNode;
    }
    this.size++;
  }

  pop(){
    let node = this.head, nodeToReturn = null, prevNode = null;
    while(node.next){
      prevNode = node;
      node = node.next;
    }
    nodeToReturn = node;
    prevNode.next = null;
    this.size--;
    return nodeToReturn
  }
}