couchpotato-linked-list/dist/ds/list/linked-list.js

DoublyLinkedList implementation in javascript

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.LinkedList = exports.Item = void 0;

function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }

function _defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } }

function _createClass(Constructor, protoProps, staticProps) { if (protoProps) _defineProperties(Constructor.prototype, protoProps); if (staticProps) _defineProperties(Constructor, staticProps); Object.defineProperty(Constructor, "prototype", { writable: false }); return Constructor; }

var Item = /*#__PURE__*/function () {
  function Item(value) {
    var next = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : null;
    var prev = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : null;

    _classCallCheck(this, Item);

    this._value = value;
    this._next = next;
    this._prev = prev;
  }

  _createClass(Item, [{
    key: "getNext",
    value: function getNext() {
      return this._next;
    }
  }, {
    key: "setNext",
    value: function setNext(item) {
      this._next = item;
      return this;
    }
  }, {
    key: "getPrev",
    value: function getPrev() {
      return this._prev;
    }
  }, {
    key: "setPrev",
    value: function setPrev(item) {
      this._prev = item;
      return this;
    }
  }, {
    key: "getValue",
    value: function getValue() {
      return this._value;
    }
  }, {
    key: "setValue",
    value: function setValue(val) {
      this._value = val;
      return this;
    }
  }, {
    key: "hasNext",
    value: function hasNext() {
      return this._next !== null;
    }
  }, {
    key: "hasPrev",
    value: function hasPrev() {
      return this._prev != null;
    }
  }]);

  return Item;
}();

exports.Item = Item;

var LinkedList = /*#__PURE__*/function () {
  function LinkedList() {
    _classCallCheck(this, LinkedList);

    this._head = null;
    this._tail = null;
    this._length = 0;
  }

  _createClass(LinkedList, [{
    key: "head",
    value: function head() {
      return this._head;
    }
  }, {
    key: "tail",
    value: function tail() {
      return this._tail;
    }
  }, {
    key: "length",
    value: function length() {
      return this._length;
    }
  }, {
    key: "append",
    value: function append(value) {
      var item = new Item(value);

      if (this._head === null) {
        this._head = item;
      } else {
        item.setPrev(this._tail);

        this._tail.setNext(item);
      }

      this._tail = item;
      this._length++;
      return this;
    }
  }, {
    key: "push",
    value: function push(value) {
      return this.append(value);
    }
  }, {
    key: "prepend",
    value: function prepend(value) {
      var item = new Item(value);

      if (this._head === null) {
        this._tail = item;
      } else {
        this._head.setPrev(item);

        item.setNext(this._head);
      }

      this._head = item;
      this._length++;
      return this;
    }
  }, {
    key: "shift",
    value: function shift(value) {
      return this.prepend(value);
    }
  }, {
    key: "removeFromFront",
    value: function removeFromFront() {
      if (this._head === null) return undefined;else {
        var item = this._head;

        if (this._length === 1) {
          this._tail = null;
          this._head = null;
        } else {
          this._head = item.getNext();

          this._head.setPrev(null);
        }

        item.setNext(null);
        item.setPrev(null);
        this._length--;
        return item;
      }
    }
  }, {
    key: "unshift",
    value: function unshift() {
      return this.removeFromFront();
    }
  }, {
    key: "removeFromEnd",
    value: function removeFromEnd() {
      if (this._head === null) return undefined;else {
        var item = this._tail;

        if (this._length === 1) {
          this._head = null;
          this._tail = null;
        } else {
          this._tail = item.getPrev();

          this._tail.setNext(null);
        }

        item.setNext(null);
        item.setPrev(null);
        this._length--;
        return item;
      }
    }
  }, {
    key: "pop",
    value: function pop() {
      return this.removeFromEnd();
    }
  }, {
    key: "getNode",
    value: function getNode(index) {
      if (index < 0 || index >= this._length) return undefined;
      var current = this._head;

      for (var i = 0; i < index; i++) {
        current = current.getNext();
      }

      return current;
    }
  }, {
    key: "get",
    value: function get(index) {
      var node = this.getNode(index);
      if (node) return node.getValue();else undefined;
    }
  }, {
    key: "removeAt",
    value: function removeAt(index) {
      var targetNode = this.getNode(index);
      var prevNode = targetNode.getPrev();
      var nextNode = targetNode.getNext(); // one node

      if (prevNode == null && nextNode == null) {
        this._head = null;
        this._tail = null;
      } // first node
      else if (prevNode == null) {
        this._head = nextNode;
        nextNode.setPrev(null);
      } //last node
      else if (nextNode == null) {
        this._tail = prevNode;
        prevNode.setNext(null);
      } // normal node
      else {
        prevNode.setNext(nextNode);
        nextNode.setPrev(prevNode);
      }

      return targetNode.getValue();
    }
  }]);

  return LinkedList;
}();

exports.LinkedList = LinkedList;