图，深度优先和广度优先算法

粘贴代码如下：

import javax.swing.*;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.LinkedList;

public class Graph {
    private ArrayList<String> vertexList;
    private int[][] edges;
    private int numOfEdges;
    private boolean[] isVisited;

    public static void main(String[] args) {
        int n = 5;
        String[] vertexs = {"A", "B", "C", "D", "E"};
        Graph graph = new Graph(n);
        for (String vertex : vertexs) {
            graph.insertVertex(vertex);
        }
        graph.insertEdge(0, 1, 1);
        graph.insertEdge(0, 2, 1);
        graph.insertEdge(1, 2, 1);
        graph.insertEdge(1, 3, 1);
        graph.insertEdge(1, 4, 1);

        // 显示一把邻接矩阵
        graph.showGraph();

//        System.out.println("深度遍历");
//        graph.dfs();

        System.out.println();
        System.out.println("广度遍历");
        graph.bfs();
    }

    public Graph(int n) {
        edges = new int[n][n];
        vertexList = new ArrayList<String>(n);
        numOfEdges = 0;
        isVisited = new boolean[n];
    }

    // 深度优先遍历算法
    private void dfs(boolean[] isVisited, int i) {
        System.out.print(getValueByIndex(i) + "->");
        isVisited[i] = true;
        int w = getFirstNeighbor(i);
        while (w != -1) {
            if (!isVisited[w]) {
                dfs(isVisited, w);
            }
            // 根据前一个邻接节点，获取下一个邻接节点
            w = getNextNeighbor(i, w);
        }
    }

    // 对dfs进行重载，遍历所有结点，进行dfs
    public void dfs() {
        for (int i=0; i < getNumOfVertex(); i++) {
            if (isVisited[i]) {
                continue;
            }
            dfs(isVisited, i);
        }
    }

    // 广度优先遍历算法
    private void bfs(boolean[] isVisited, int i) {
        int u;
        int w;
        LinkedList queue = new LinkedList();
        System.out.print(getValueByIndex(i) + "=>");
        isVisited[i] = true;
        queue.addLast(i);

        while ( !queue.isEmpty()) {
            u = (Integer) queue.removeFirst();
            w = getFirstNeighbor(u);
            while (w != -1) {
                if (!isVisited[w]) {
                    System.out.print(getValueByIndex(w) + "=>");
                    isVisited[w] = true;
                    queue.addLast(w);
                }
                // 根据结点u，查找w后面的一个邻结点，递归查找
                w = getNextNeighbor(u, w);
            }
        }
    }

    // 对bfs进行重载，遍历所有结点
    public void bfs() {
        for (int i = 0; i < getNumOfVertex(); i++) {
            if (isVisited[i]) {
                continue;
            }
            bfs(isVisited, i);
        }
    }

    // 获取第一个邻接节点的下标w
    public int getFirstNeighbor(int index) {
        for (int j = 0; j < vertexList.size(); j++) {
            if (edges[index][j] > 0) {
                return j;
            }
        }
        return -1;
    }

    // 根据前一个邻接节点，获取下一个邻接节点
    public int getNextNeighbor(int v1, int v2) {
        for (int j = v2 + 1; j < vertexList.size(); j++) {
            if(edges[v1][j] > 0) {
                return j;
            }
        }
        return -1;
    }

    public void insertVertex(String vertex) {
        vertexList.add(vertex);
    }

    public void insertEdge(int v1, int v2, int weight) {
        edges[v1][v2] = weight;
        edges[v2][v1] = weight;
        numOfEdges++;
    }

    public String getValueByIndex(int i) {
        return vertexList.get(i);
    }

    public int getNumOfVertex() {
        return vertexList.size();
    }

    public int getNumOfEdges() {
        return numOfEdges;
    }

    public void showGraph() {
        for (int[] link : edges) {
            System.err.println(Arrays.toString(link));
        }
    }
}