What are some common graph algorithms implemented in Java?

What are some common graph algorithms implemented in Java?

Some common graph algorithms in Java include Dijkstra's algorithm, A* search, and Depth-First Search (DFS). Would you like to know more about any specific algorithm?

Can you explain Dijkstra's algorithm?

Dijkstra's algorithm finds the shortest path from a source node to all other nodes in a weighted graph. It uses a priority queue to explore the nearest unvisited node.

How do I implement Dijkstra's algorithm in Java?

You can implement Dijkstra's algorithm using a priority queue and an adjacency list. Would you like a code example?

Yes, please provide a code example.

Here's a simple implementation of Dijkstra's algorithm in Java:

import java.util.*;

class Graph {
    private final int V;
    private final List<List<Node>> adj;

    public Graph(int v) {
        V = v;
        adj = new ArrayList<>(v);
        for (int i = 0; i < v; i++) {
            adj.add(new ArrayList<>());
        }
    }

    public void addEdge(int u, int v, int w) {
        adj.get(u).add(new Node(v, w));
    }

    public void dijkstra(int src) {
        int[] dist = new int[V];
        Arrays.fill(dist, Integer.MAX_VALUE);
        dist[src] = 0;

        PriorityQueue<Node> pq = new PriorityQueue<>(Comparator.comparingInt(node -> node.weight));
        pq.add(new Node(src, 0));

        while (!pq.isEmpty()) {
            Node node = pq.poll();
            for (Node neighbor : adj.get(node.vertex)) {
                if (dist[node.vertex] + neighbor.weight < dist[neighbor.vertex]) {
                    dist[neighbor.vertex] = dist[node.vertex] + neighbor.weight;
                    pq.add(new Node(neighbor.vertex, dist[neighbor.vertex]));
                }
            }
        }
        System.out.println(Arrays.toString(dist));
    }
}

class Node {
    int vertex, weight;
    Node(int v, int w) { vertex = v; weight = w; }
}

This code defines a graph and implements Dijkstra's algorithm to find the shortest paths.