multiprocessing/build/heap.js

Dead simple parallel processing for node

'use strict';

var _createClass = 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); } } return function (Constructor, protoProps, staticProps) { if (protoProps) defineProperties(Constructor.prototype, protoProps); if (staticProps) defineProperties(Constructor, staticProps); return Constructor; }; }();

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

var newHeapNode = function newHeapNode(elem, data) {
  return {
    elem: elem,
    data: data,
    child: null,
    next: null
  };
};

var Heap = function () {
  function Heap() {
    _classCallCheck(this, Heap);

    this.root = null;
    this.len = 0;
  }

  _createClass(Heap, [{
    key: 'popMax',
    value: function popMax() {
      if (!this.len) {
        return null;
      }
      var max = this.root;
      this.len -= 1;
      this.root = this.mergePairs(this.root.child);
      return max;
    }
  }, {
    key: 'insert',
    value: function insert(elem, data) {
      this.root = this.merge(this.root, newHeapNode(elem, data));
      return ++this.len;
    }
  }, {
    key: 'link',
    value: function link(parent, child) {
      var firstChild = parent.child;
      parent.child = child;
      child.next = firstChild;
    }
  }, {
    key: 'merge',
    value: function merge(heap1, heap2) {
      if (!heap1 || !heap2) {
        return heap1 || heap2;
      }

      if (heap1.elem > heap2.elem) {
        this.link(heap1, heap2);
        return heap1;
      }

      this.link(heap2, heap1);
      return heap2;
    }
  }, {
    key: 'mergePairs',
    value: function mergePairs(heapLL) {
      var paired = [];
      while (heapLL && heapLL.next) {
        var heap1 = heapLL;
        var heap2 = heap1.next;
        heapLL = heap2.next;
        paired.push(this.merge(heap1, heap2));
      }
      if (heapLL) {
        paired.push(heapLL);
      }

      var newRoot = paired.pop();
      while (paired.length) {
        var heap = paired.pop();
        newRoot = this.merge(heap, newRoot);
      }

      return newRoot;
    }
  }]);

  return Heap;
}();

module.exports = Heap;