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65 lines
1.9 KiB
JavaScript
65 lines
1.9 KiB
JavaScript
(function (exports) {
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'use strict';
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var bfs = (function () {
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function buildPath(parents, targetNode) {
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var result = [targetNode];
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while (parents[targetNode] !== null) {
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targetNode = parents[targetNode];
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result.push(targetNode);
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}
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return result.reverse();
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}
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/**
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* Breath-First graph searching algorithm.
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* Returns the shortest path between startNode and targetNode.<br><br>
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* Time complexity: O(|V|^2).
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*
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* @public
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* @module graphs/searching/bfs
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* @param {Array} graph Adjacency matrix, which represents the graph.
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* @param {Number} startNode Start node.
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* @param {Number} targetNode Target, which should be reached.
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* @returns {Array} Shortest path from startNode to targetNode.
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*
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* @example
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* var bfs = require('path-to-algorithms/src/graphs/searching/bfs').bfs;
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* var graph = [[1, 1, 0, 0, 1, 0],
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* [1, 0, 1, 0, 1, 0],
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* [0, 1, 0, 1, 0, 0],
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* [0, 0, 1, 0, 1, 1],
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* [1, 1, 0, 1, 0, 0],
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* [0, 0, 0, 1, 0, 0]];
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* var shortestPath = bfs(graph, 1, 5); // [1, 2, 3, 5]
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*/
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return function (graph, startNode, targetNode) {
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var parents = [];
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var queue = [];
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var visited = [];
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var current;
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queue.push(startNode);
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parents[startNode] = null;
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visited[startNode] = true;
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while (queue.length) {
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current = queue.shift();
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if (current === targetNode) {
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return buildPath(parents, targetNode);
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}
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for (var i = 0; i < graph.length; i += 1) {
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if (i !== current && graph[current][i] && !visited[i]) {
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parents[i] = current;
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visited[i] = true;
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queue.push(i);
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}
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}
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}
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return null;
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};
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}());
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exports.bfs = bfs;
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}((typeof window === 'undefined') ? module.exports : window));
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