DataStructure_LinkedList.js

class LinkedList {
  constructor() {
    this.length = 0;
    this.head = null;
    this.tail = null;
  }

  add(value) {
    if (this.head) {
      // while문을 탈출한 다음은 next가 null인 상태!
      this.current.next = new Node(value);
    } else {
      this.head = new Node(value);
      this.tail = this.head.next;
    }
    this.length++;
    return this.length; // add하면서 길이 늘어나는거 확인하라고 length 반환.
  }

  search(index) {
    return this.#search(index)[1]?.value;
  }
  #search(index) {
    let count = 0;
    let prev;
    let current = this.head;
    while (count < index) {
      prev = current;
      current = current?.next;
      count++;
    }
    return [prev, current];
  }

  remove(index) {
    const [prev, current] = this.#search(index);
    if (prev && current) {
      prev.next = current?.next;
      this.length--;
      return this.length;
    } else if (current) {
      // index가 0일 때,
      this.head = current.next;
    }
    // 삭제하고자 하는 대상이 없을 때,
    // 아무것도 안 함
  }
}

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

const ll = new LinkedList();
ll.add(1);
ll.add(2);
ll.add(3);
ll.add(4);
console.log(ll);
console.log(ll.search(3));