This Java program to find mst using kruskal’s algorithm.Kruskal’s algorithm is a greedy algorithm in graph theory that finds a minimum spanning tree for a connected weighted graph. This means it finds a subset of the edges that forms a tree that includes every vertex, where the total weight of all the edges in the tree is minimized
Here is the source code of the Java program to find mst using kruskal’s algorithm. The Java program is successfully compiled and run on a Linux system. The program output is also shown below.
import java.util.Collections; import java.util.Comparator; import java.util.LinkedList; import java.util.List; import java.util.Scanner; import java.util.Stack; public class KruskalAlgorithm { private List<Edge> edges; private int numberOfVertices; public static final int MAX_VALUE = 999; private int visited[]; private int spanning_tree[][]; public KruskalAlgorithm(int numberOfVertices) { this.numberOfVertices = numberOfVertices; edges = new LinkedList<Edge>(); visited = new int[this.numberOfVertices + 1]; spanning_tree = new int[numberOfVertices + 1][numberOfVertices + 1]; } public void kruskalAlgorithm(int adjacencyMatrix[][]) { boolean finished = false; for (int source = 1; source <= numberOfVertices; source++) { for (int destination = 1; destination <= numberOfVertices; destination++) { if (adjacencyMatrix[destination] != MAX_VALUE && source != destination) { Edge edge = new Edge(); edge.sourcevertex = source; edge.destinationvertex = destination; edge.weight = adjacencyMatrix[destination]; adjacencyMatrix[destination] = MAX_VALUE; edges.add(edge); } } } Collections.sort(edges, new EdgeComparator()); CheckCycle checkCycle = new CheckCycle(); for (Edge edge : edges) { spanning_tree[edge.sourcevertex][edge.destinationvertex] = edge.weight; spanning_tree[edge.destinationvertex][edge.sourcevertex] = edge.weight; if (checkCycle.checkCycle(spanning_tree, edge.sourcevertex)) { spanning_tree[edge.sourcevertex][edge.destinationvertex] = 0; spanning_tree[edge.destinationvertex][edge.sourcevertex] = 0; edge.weight = -1; continue; } visited[edge.sourcevertex] = 1; visited[edge.destinationvertex] = 1; for (int i = 0; i < visited.length; i++) { if (visited[i] == 0) { finished = false; break; } else { finished = true; } } if (finished) break; } System.out.println("The spanning tree is "); for (int i = 1; i <= numberOfVertices; i++) System.out.print("\t" + i); System.out.println(); for (int source = 1; source <= numberOfVertices; source++) { System.out.print(source + "\t"); for (int destination = 1; destination <= numberOfVertices; destination++) { System.out.print(spanning_tree[destination] + "\t"); } System.out.println(); } } public static void main(String... arg) { int adjacency_matrix[][]; int number_of_vertices; Scanner scan = new Scanner(System.in); System.out.println("Enter the number of vertices"); number_of_vertices = scan.nextInt(); adjacency_matrix = new int[number_of_vertices + 1][number_of_vertices + 1]; System.out.println("Enter the Weighted Matrix for the graph"); for (int i = 1; i <= number_of_vertices; i++) { for (int j = 1; j <= number_of_vertices; j++) { adjacency_matrix[i][j] = scan.nextInt(); if (i == j) { adjacency_matrix[i][j] = 0; continue; } if (adjacency_matrix[i][j] == 0) { adjacency_matrix[i][j] = MAX_VALUE; } } } KruskalAlgorithm kruskalAlgorithm = new KruskalAlgorithm(number_of_vertices); kruskalAlgorithm.kruskalAlgorithm(adjacency_matrix); scan.close(); } } class Edge { int sourcevertex; int destinationvertex; int weight; } class EdgeComparator implements Comparator<Edge> { @Override public int compare(Edge edge1, Edge edge2) { if (edge1.weight < edge2.weight) return -1; if (edge1.weight > edge2.weight) return 1; return 0; } } class CheckCycle { private Stack<Integer> stack; private int adjacencyMatrix[][]; public CheckCycle() { stack = new Stack<Integer>(); } public boolean checkCycle(int adjacency_matrix[][], int source) { boolean cyclepresent = false; int number_of_nodes = adjacency_matrix.length - 1; adjacencyMatrix = new int[number_of_nodes + 1][number_of_nodes + 1]; for (int sourcevertex = 1; sourcevertex <= number_of_nodes; sourcevertex++) { for (int destinationvertex = 1; destinationvertex <= number_of_nodes; destinationvertex++) { adjacencyMatrix[sourcevertex][destinationvertex] = adjacency_matrix[sourcevertex[destinationvertex]; } } int visited[] = new int[number_of_nodes + 1]; int element = source; int i = source; visited = 1; stack.push(source); while (!stack.isEmpty()) { element = stack.peek(); i = element; while (i <= number_of_nodes) { if (adjacencyMatrix[element][i] >= 1 && visited[i] == 1) { if (stack.contains(i)) { cyclepresent = true; return cyclepresent; } } if (adjacencyMatrix[element][i] >= 1 && visited[i] == 0) { stack.push(i); visited[i] = 1; adjacencyMatrix[element][i] = 0;// mark as labelled; adjacencyMatrix[i][element] = 0; element = i; i = 1; continue; } i++; } stack.pop(); } return cyclepresent; } }
$javac KruskalAlgorithm.java $java KruskalAlgorithm Enter the number of vertices 6 Enter the Weighted Matrix for the graph 0 6 8 6 0 0 6 0 0 5 10 0 8 0 0 7 5 3 6 5 7 0 0 0 0 10 5 0 0 3 0 0 3 0 3 0 The spanning tree is 1 2 3 4 5 6 1 0 6 0 0 0 0 2 6 0 0 5 0 0 3 0 0 0 7 0 3 4 0 5 7 0 0 0 5 0 0 0 0 0 3 6 0 0 3 0 3 0
Related posts:
Jackson Ignore Properties on Marshalling
A Guide to the finalize Method in Java
Java Program to Perform Stooge Sort
Runnable vs. Callable in Java
Hướng dẫn Java Design Pattern – Proxy
Composition, Aggregation, and Association in Java
Java Program to implement Array Deque
A Guide to Java HashMap
Introduction to Liquibase Rollback
ETags for REST with Spring
Hướng dẫn sử dụng Lớp FilePermission trong java
Java Program to Solve TSP Using Minimum Spanning Trees
Spring @RequestParam Annotation
Tổng quan về ngôn ngữ lập trình java
Hướng dẫn Java Design Pattern – Abstract Factory
Java equals() and hashCode() Contracts
ArrayList trong java
Guide to Java Instrumentation
Understanding Memory Leaks in Java
Spring Boot Gradle Plugin
Send email with authentication
Converting Strings to Enums in Java
Iterable to Stream in Java
Java Program to Implement Double Order Traversal of a Binary Tree
Java Program to Permute All Letters of an Input String
Hướng dẫn sử dụng biểu thức chính quy (Regular Expression) trong Java
Send an email using the SMTP protocol
Java Program to Generate Random Hexadecimal Byte
Java Program to Implement the Edmond’s Algorithm for Maximum Cardinality Matching
Optional trong Java 8
Guide to PriorityBlockingQueue in Java
Java Program to Perform Polygon Containment Test