如何用Java实现图的遍历 Java图的DFS和BFS算法示例

import java.util.*;

class Graph {
    private int vertices;
    private LinkedList<Integer>[] adjList;

    Graph(int vertices) {
        this.vertices = vertices;
        adjList = new LinkedList[vertices];
        for (int i = 0; i < vertices; i++) {
            adjList[i] = new LinkedList<>();
        }
    }

    void addEdge(int src, int dest) {
        adjList[src].add(dest);
    }

    // DFS 算法
    void DFS(int startVertex) {
        boolean[] visited = new boolean[vertices];
        DFSUtil(startVertex, visited);
    }

    private void DFSUtil(int vertex, boolean[] visited) {
        visited[vertex] = true;
        System.out.print(vertex + " ");

        Iterator<Integer> it = adjList[vertex].listIterator();
        while (it.hasNext()) {
            int next = it.next();
            if (!visited[next]) {
                DFSUtil(next, visited);
            }
        }
    }

    // BFS 算法
    void BFS(int startVertex) {
        boolean[] visited = new boolean[vertices];
        LinkedList<Integer> queue = new LinkedList<>();

        visited[startVertex] = true;
        queue.add(startVertex);

        while (queue.size() != 0) {
            int vertex = queue.poll();
            System.out.print(vertex + " ");

            Iterator<Integer> it = adjList[vertex].listIterator();
            while (it.hasNext()) {
                int next = it.next();
                if (!visited[next]) {
                    visited[next] = true;
                    queue.add(next);
                }
            }
        }
    }

    public static void main(String[] args) {
        Graph g = new Graph(6);
        g.addEdge(0, 1);
        g.addEdge(0, 2);
        g.addEdge(1, 2);
        g.addEdge(2, 0);
        g.addEdge(2, 3);
        g.addEdge(3, 3);
        g.addEdge(4,5);

        System.out.println("DFS starting from vertex 2:");
        g.DFS(2);  // Output: 2 0 1 3

        System.out.println("\nBFS starting from vertex 2:");
        g.BFS(2); // Output: 2 0 3 1
    }
}