// https://www.freecodecamp.org/learn/coding-interview-prep/data-structures/remove-elements-from-a-linked-list

function LinkedList() {
  var length = 0;
  var head = null;

  var Node = function (element) {
    this.element = element;
    this.next = null;
  };

  this.size = function () {
    return length;
  };

  this.head = function () {
    return head;
  };

  this.add = function (element) {
    var node = new Node(element);
    if (head === null) {
      head = node;
    } else {
      var currentNode = head;

      while (currentNode.next) {
        currentNode = currentNode.next;
      }

      currentNode.next = node;
    }

    length++;
  };

  this.remove = function (element) {
    // Only change code below this line
    let previous = null;
    let current = head;
    while (current !== null && current.element !== element) {
      previous = current;
      current = current.next;
    }
    if (current === null) {
      return;
    }
    if (previous === null) {
      head = current.next;
    } else {
      previous.next = current.next;
    }
    length--;
    // Only change code above this line
  };
}