DijkstrasAlgorithm.java

import java.util.*;

public class DijkstrasAlgorithm {
    private static final int INF = Integer.MAX_VALUE;

    public static void dijkstra(int[][] graph, int start) {
        int V = graph.length;
        int[] dist = new int[V];
        boolean[] visited = new boolean[V];

        Arrays.fill(dist, INF);
        dist[start] = 0;

        for (int count = 0; count < V - 1; count++) {
            int u = minDistance(dist, visited);
            visited[u] = true;

            for (int v = 0; v < V; v++) {
                if (!visited[v] && graph[u][v] != 0 && dist[u] != INF && dist[u] + graph[u][v] < dist[v]) {
                    dist[v] = dist[u] + graph[u][v];
                }
            }
        }

        printSolution(dist);
    }

    private static int minDistance(int[] dist, boolean[] visited) {
        int V = dist.length;
        int min = INF;
        int minIndex = -1;

        for (int v = 0; v < V; v++) {
            if (!visited[v] && dist[v] <= min) {
                min = dist[v];
                minIndex = v;
            }
        }

        return minIndex;
    }

    private static void printSolution(int[] dist) {
        int V = dist.length;
        System.out.println("Vertex \t Distance from Source");
        for (int i = 0; i < V; i++) {
            System.out.println(i + " \t " + dist[i]);
        }
    }

    public static void main(String[] args) {
        int[][] graph = {
            {0, 4, 0, 0, 0, 0, 0, 8, 0},
            {4, 0, 8, 0, 0, 0, 0, 11, 0},
            {0, 8, 0, 7, 0, 4, 0, 0, 2},
            {0, 0, 7, 0, 9, 14, 0, 0, 0},
            {0, 0, 0, 9, 0, 10, 0, 0, 0},
            {0, 0, 4, 14, 10, 0, 2, 0, 0},
            {0, 0, 0, 0, 0, 2, 0, 1, 6},
            {8, 11, 0, 0, 0, 0, 1, 0, 7},
            {0, 0, 2, 0, 0, 0, 6, 7, 0}
        };

        dijkstra(graph, 0);
    }
}