【算法】图的广度优先搜索和深度优先搜索

我们构建一张如下的图：

直接上代码：

package main;

import java.util.ArrayList;

public class Node {
    private String name = "";
    public ArrayList<Node> neighbor = new ArrayList<>();
    public boolean flag = false;

    public Node(String name){
        this.name = name;
    }

    public void addNeighbor(Node... nodes){
        if(nodes != null){
            for(Node temp:nodes){
                neighbor.add(temp);
            }
        }
    }

    public String getName(){
        return name;
    }
}

 1 package main;
 2
 3 import java.util.ArrayList;
 4 import java.util.LinkedList;
 5 import java.util.Queue;
 6 import java.util.Stack;
 7 import java.util.concurrent.ExecutorService;
 8 import java.util.concurrent.Executors;
 9 import java.util.concurrent.locks.Condition;
10 import java.util.concurrent.locks.Lock;
11 import java.util.concurrent.locks.ReentrantLock;
12
13 public class Main {
14     public static void main(String[] args){
15         Node a = new Node("A");
16         Node b = new Node("B");
17         Node c = new Node("C");
18         Node d = new Node("D");
19         Node e = new Node("E");
20         Node f = new Node("F");
21         Node g = new Node("G");
22         Node h = new Node("H");
23         Node i = new Node("I");
24
25         a.addNeighbor(b,f);
26         b.addNeighbor(a,g,i,c);
27         c.addNeighbor(b,i,d);
28         d.addNeighbor(c,i,g,h,e);
29         e.addNeighbor(d,h,f);
30         f.addNeighbor(a,g,e);
31         h.addNeighbor(g,d,e);
32         i.addNeighbor(b,c,d);
33
34         //深度优先
35         Stack<Node> stack = new Stack<>();
36         stack.push(a);
37         a.flag = true;
38         while(!stack.isEmpty()){
39             Node curNode = stack.pop();
40             System.out.print(curNode.getName());
41             for(Node temp:curNode.neighbor){
42                 if(temp.flag == false){
43                     stack.push(temp);
44                     temp.flag = true;
45                 }
46             }
47         }
48         System.out.println("\n");
49
50         a.flag = false;
51         b.flag = false;
52         c.flag = false;
53         d.flag = false;
54         g.flag = false;
55         e.flag = false;
56         f.flag = false;
57         h.flag = false;
58         i.flag = false;
59
60         //广度优先
61         Queue<Node> queue = new LinkedList<>();
62         queue.offer(a);
63         a.flag = true;
64         while(!queue.isEmpty()){
65             Node curNode = queue.poll();
66             System.out.print(curNode.getName());
67             for(Node temp:curNode.neighbor){
68                 if(temp.flag == false){
69                     queue.offer(temp);
70                     temp.flag = true;
71                 }
72             }
73         }
74
75         System.out.print("\n");
76     }
77
78 }

输出结果分别为：

AFEHDICGB

ABFGICEDH

原文地址：https://www.cnblogs.com/yanyojun/p/9488759.html