/**
* Keeps track of a set of elements partitioned into a
* number of disjoint (nonoverlapping) subsets.
* Allows to check whether the path between two nodes exists.
* <br>
* The algorithm is inspired by Robert Sedgewick's Java implementation.
* {@link http://algs4.cs.princeton.edu/home/}
*
* @example
*
* var QuickUnion = require('path-to-algorithms/' +
* 'src/sets/quickunion').QuickUnion;
*
* var qunion = new QuickUnion(10);
* qunion.union(0, 1);
* qunion.union(2, 1);
* qunion.union(3, 4);
* qunion.union(8, 9);
* qunion.union(4, 8);
*
* console.log(qunion.connected(0, 9)); // false
* console.log(qunion.connected(3, 9)); // true
*
* @public
* @module sets/quickunion
*/
(function (exports) {
'use strict';
/**
* Initialization.<br><br>
* Time complexity: O(N).
*
* @public
* @constructor
* @param {Numner} size Count of the nodes.
*/
exports.QuickUnion = function (n) {
this._ids = [];
for (var i = 0; i < n; i += 1) {
this._ids[i] = i;
}
};
/**
* Finds the root of given node.<br><br>
* Time complexity: O(N).
* @private
* @param {Number} i The given node.
* @return {Number} Root of the given node.
*/
exports.QuickUnion.prototype._root = function (i) {
while (i !== this._ids[i]) {
i = this._ids[i];
}
return i;
};
/**
* Connects two nodes - p and q.<br><br>
* Time complexity: O(N).
*
* @public
* @method
* @param {Number} p The first node.
* @param {Number} q The second node.
*/
exports.QuickUnion.prototype.union = function (p, q) {
var pRoot = this._root(p);
var qRoot = this._root(q);
this._ids[pRoot] = qRoot;
};
/**
* Checks whether two nodes are connected.<br><br>
* Time complexity: O(N).
*
* @param {Number} p The first node.
* @param {Number} q The second node.
* @return {Boolean} True/false depending on whether the nodes are connected.
*/
exports.QuickUnion.prototype.connected = function (p, q) {
return this._root(p) === this._root(q);
};
})(typeof window === 'undefined' ? module.exports : window);