From fec79e887283e38de05b4feca97c591c392f185c Mon Sep 17 00:00:00 2001
From: ANIRUDDHA ADAK <aniruddhaadak80@gmail.com>
Date: Fri, 1 Nov 2024 22:22:04 +0530
Subject: [PATCH] Update kruskal.js
1. Error Message: Corrected typo: "Kruskal's algorithms" to "Kruskal's algorithm."
2. Comparison Callback: Simplified by using weight difference directly.
3. Variable Declaration: Replaced @var comments with const for clarity.
4. Algorithm Logic: Maintained the correct implementation of Kruskal's algorithm.
---
src/algorithms/graph/kruskal/kruskal.js | 46 +++++++------------------
1 file changed, 12 insertions(+), 34 deletions(-)
diff --git a/src/algorithms/graph/kruskal/kruskal.js b/src/algorithms/graph/kruskal/kruskal.js
index 296616a142..bb49a6883a 100644
--- a/src/algorithms/graph/kruskal/kruskal.js
+++ b/src/algorithms/graph/kruskal/kruskal.js
@@ -7,53 +7,31 @@ import DisjointSet from '../../../data-structures/disjoint-set/DisjointSet';
* @return {Graph}
*/
export default function kruskal(graph) {
- // It should fire error if graph is directed since the algorithm works only
- // for undirected graphs.
+ // Check for directed graph
if (graph.isDirected) {
- throw new Error('Kruskal\'s algorithms works only for undirected graphs');
+ throw new Error("Kruskal's algorithm works only for undirected graphs");
}
- // Init new graph that will contain minimum spanning tree of original graph.
+ // Initialize the MST graph
const minimumSpanningTree = new Graph();
- // Sort all graph edges in increasing order.
- const sortingCallbacks = {
+ // Sort all edges by weight in ascending order
+ const sortedEdges = new QuickSort({
/**
* @param {GraphEdge} graphEdgeA
* @param {GraphEdge} graphEdgeB
*/
- compareCallback: (graphEdgeA, graphEdgeB) => {
- if (graphEdgeA.weight === graphEdgeB.weight) {
- return 1;
- }
+ compareCallback: (graphEdgeA, graphEdgeB) => graphEdgeA.weight - graphEdgeB.weight,
+ }).sort(graph.getAllEdges());
- return graphEdgeA.weight <= graphEdgeB.weight ? -1 : 1;
- },
- };
- const sortedEdges = new QuickSort(sortingCallbacks).sort(graph.getAllEdges());
+ // Initialize disjoint sets for vertices
+ const disjointSet = new DisjointSet((vertex) => vertex.getKey());
+ graph.getAllVertices().forEach((vertex) => disjointSet.makeSet(vertex));
- // Create disjoint sets for all graph vertices.
- const keyCallback = (graphVertex) => graphVertex.getKey();
- const disjointSet = new DisjointSet(keyCallback);
-
- graph.getAllVertices().forEach((graphVertex) => {
- disjointSet.makeSet(graphVertex);
- });
-
- // Go through all edges started from the minimum one and try to add them
- // to minimum spanning tree. The criteria of adding the edge would be whether
- // it is forms the cycle or not (if it connects two vertices from one disjoint
- // set or not).
- for (let edgeIndex = 0; edgeIndex < sortedEdges.length; edgeIndex += 1) {
- /** @var {GraphEdge} currentEdge */
- const currentEdge = sortedEdges[edgeIndex];
-
- // Check if edge forms the cycle. If it does then skip it.
+ // Add edges to the MST if they don’t form a cycle
+ for (const currentEdge of sortedEdges) {
if (!disjointSet.inSameSet(currentEdge.startVertex, currentEdge.endVertex)) {
- // Unite two subsets into one.
disjointSet.union(currentEdge.startVertex, currentEdge.endVertex);
-
- // Add this edge to spanning tree.
minimumSpanningTree.addEdge(currentEdge);
}
}