Graph representation(Both directed and undirected) using adjacency list (code in JAVA)

import java.util.ArrayList;

import java.util.Scanner;

public class graph {

    public static void main(String[] args) {

        Scanner scanner = new Scanner(System.in);

        // Input the number of nodes.

        System.out.print("Enter the number of nodes: ");

        int numNodes = scanner.nextInt();

        // Create an adjacency list.

        ArrayList<ArrayList<Integer>> adjList = new ArrayList<>(numNodes);

        for (int i = 0; i < numNodes + 1; i++) { // numNodes + 2 only if remove empty zero index 

            adjList.add(new ArrayList<>());

        }

        // Input the number of edges.

        System.out.print("Enter the number of edges: ");

        int numEdges = scanner.nextInt();

        // Input the edges (connections between nodes).

        System.out.println("Enter the edges (startNode endNode):");

        for (int i = 0; i < numEdges; i++) {

            int startNode = scanner.nextInt();

            int endNode = scanner.nextInt();

            // Add an edge from startNode to endNode (for directed graph).

            adjList.get(startNode).add(endNode);

            // For undirected graph, add the reverse edge as well.

            // adjList.get(endNode).add(startNode); // Uncomment this line for an undirected graph.

        }

        // Print the adjacency list.

        System.out.println("Adjacency List:");

        for (int i = 1; i < numNodes + 1; i++) {

            System.out.print(i + " -> ");

            for (int neighbor : adjList.get(i)) {

                System.out.print(neighbor + " ");

            }

            System.out.println();

        }

        scanner.close();

    }

}