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