DFS+BFS

import java.util.*;

//以無向圖為例，實現圖的深度優先搜尋和廣度優先搜尋

class Graph{
	public int[][] adjacencyMatrix;//鄰接矩陣，1代表有邊，0代表沒有邊
	public int arcNumber;//邊數
	public int vertexNumber;//頂點數
	public boolean[] visited;

	public void createGraph(){
		Scanner scan = new Scanner(System.in);
		System.out.print("請輸入圖的頂點數："
 
);
		this.vertexNumber = scan.nextInt();
		System.out.print("請輸入圖的邊數：");
		this.arcNumber = scan.nextInt();

		this.adjacencyMatrix = new int[vertexNumber][vertexNumber];
		this.visited = new boolean[vertexNumber];
		
		for(int i = 0; i < vertexNumber; i++){
			for(int j = 0; j < vertexNumber; j++
 
){
				adjacencyMatrix[i][j] = 0;	
			}
		}		

		System.out.println("各條邊如下（頂點+空格+頂點）：");
		for(int i = 0; i < arcNumber; i++){
			int v1 = scan.nextInt();
			int v2 = scan.nextInt();
			adjacencyMatrix[v1-1][v2-1] = adjacencyMatrix[v2-1][v1-1] = 1;
		}
	}

	public void init(){
		for(int i = 0; i <
 
 vertexNumber; i++){
			visited[i] = false;
		}
	}

	//深度優先搜尋
	public void dfs(int v){
		if(visited[v] == false){
			System.out.print((v+1)+" ");
			visited[v] = true;
		}
		for(int i = 0; i < vertexNumber; i++){
			if(visited[i] == false && adjacencyMatrix[i][v] == 1){
				dfs(i);
			}
		}
	}
	//廣度優先搜尋
	public void bfs(int v){
		ArrayDeque<Integer> queue = new ArrayDeque<Integer>();
		if(visited[v] == false){
			System.out.print((v+1)+" ");
			visited[v] = true;
			queue.add(v);
		}
		while(queue.isEmpty() == false){
			int front = queue.remove();
			for(int i = 0; i < vertexNumber; i++){
				if(adjacencyMatrix[front][i] == 1 && visited[i] == false){
					queue.add(i);
					visited[i] = true;
					System.out.print((i+1)+" ");
				}
			}
		}
		System.out.println();
	}
}

public class Main {

	public static void main(String[] args){
		Graph graph = new Graph();
		graph.createGraph();
		graph.init();
		graph.dfs(0);
		System.out.println();

		graph.init();
		graph.bfs(0);
	}
	
	
}