CS/Algorithm

[백준:1260번] DFS와 BFS - JAVA

yujindonut 2021. 5. 2. 19:13
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import java.util.LinkedList;
import java.util.Queue;
import java.util.Scanner;

public class Main {

	static int map[][];
	static boolean visit[];
	static int N, M;

	private static void init(boolean[] visit) {
		
		for(int i = 1; i <= N; i++) {
			visit[i] = false;
		}	
	}
	
	public static void main(String[] args) {
		
		Scanner scan = new Scanner(System.in);
		
		N = scan.nextInt(); //정점의 개수
		M = scan.nextInt(); //간선의 개수
		int startV = scan.nextInt(); //탐색을 시작할 정점의 번호
		
		map = new int[N+1][N+1];
		visit = new boolean[N+1];
		
		init(visit);
		
		for(int i = 1; i <= M; i++) {
			
			int x = scan.nextInt();
			int y = scan.nextInt();
			
			map[x][y] = map[y][x] = 1;
		}
		
		dfs(startV);
		init(visit);
		System.out.println();
		bfs(startV);
		
		scan.close();
	}
	public static void dfs(int v) {
		
		visit[v] = true;
		System.out.print(v + " ");
		for(int i = 1; i <= N; i++) {
			if(map[v][i] == 1 && visit[i] == false) {				
				dfs(i);
			}
		}
	}
	
	public static void bfs(int v) {
		
		Queue<Integer> q = new LinkedList<>();
		q.add(v);
		visit[v] = true;

		while(!q.isEmpty()) {
			int n = q.poll();
			System.out.print(n+" ");
			for(int i = 1; i <= N; i++) {
				if(map[n][i] == 1 && !visit[i]) {
					q.add(i);
					visit[i] = true;
				}
			}
		}
	}
}
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