src/BinomialTreeWithParent.js

export default function BinomialTreeWithParent(value, children) {
	this.value = value;
	this.children = children;
	this.parent = null;
}

BinomialTreeWithParent.prototype.rank = function () {
	return this.children.length;
};

/**
 * /!\ Can only be used to merge two trees of the same rank.
 * /!\ Modifies both trees
 */

BinomialTreeWithParent.prototype.merge = function (predicate, other) {
	if (predicate(this.value, other.value) <= 0) {
		this.children = this.children.concat(other);
		other.parent = this;
		return this;
	}

	other.children = other.children.concat(this);
	this.parent = other;
	return other;
};

/**
 * Method used to reset a tree element in order to reuse it
 * somewhere else, e.g. insert it back in the same or a new
 * heap.
 */

BinomialTreeWithParent.prototype.detach = function () {
	this.children.splice(0);
	this.parent = null;
	return this;
};

BinomialTreeWithParent.prototype.setparent = function (parent) {
	this.parent = parent;
};