백준 14502 java

https://www.acmicpc.net/problem/14502

14502번: 연구소

import java.util.LinkedList;
import java.util.Queue;
import java.util.Scanner;

class Pair {
    int x;
    int y;
    Pair(int x, int y) {
        this.x = x;
        this.y = y;
    }
}

public class Main {	
	static int BLANK = 0;
    static int WALL = 1;
    static int VIRUS = 2;
    static int dx[] = {0,0,1,-1};
    static int dy[] = {1,-1,0,0};
	
    static int n;
	static int m;
    static int inputAry[][];
    static int map[][];
    static int answer = Integer.MIN_VALUE;
    
	public static void main(String[] args) {
		 	Scanner sc = new Scanner(System.in);
	        n = sc.nextInt();
	        m = sc.nextInt();
			
	        inputAry = new int[n][m];
	        map = new int[n][m];
			
	        for(int i = 0; i < n; i++)
	            for(int j = 0 ; j < m; j++)
	                inputAry[i][j] = map[i][j] = sc.nextInt();

			
	        for(int i = 0; i < n; i++) {
	            for(int j = 0 ; j < m; j++) {
	                if(inputAry[i][j] == BLANK) {
	                    map[i][j] = WALL;
	                    dfs(1);
	                    map[i][j] = BLANK;
	                }
	            }
	        }
	        System.out.println(answer);
	    }
	
	
	    static void dfs(int cnt) {	
	        if(cnt == 3) {
	            bfs();
	            return;
	        }
	        for(int i = 0; i < n; i++) {
	            for(int j = 0 ; j < m; j++) {
	                if(map[i][j] == BLANK) {
	                    map[i][j] = WALL;
						dfs(cnt+1);
	                    map[i][j] = BLANK;
	                }
	            }
	        }
	    }
	    
	    
	    static void bfs() {
	        int virusMap[][] = new int[n][m];
	        for(int i = 0; i < n; i++)
	            for(int j = 0; j < m; j++)
	                virusMap[i][j] = map[i][j];

	        Queue<Pair> q = new LinkedList<Pair>();
	        
	        for(int i = 0; i < n; i++)
	            for(int j = 0; j < m; j++)
	                if(virusMap[i][j] == VIRUS)
	                    q.add(new Pair(i,j));

	        while(!q.isEmpty()) {
	            Pair p = q.remove();
	            int x = p.x;
	            int y = p.y;
	            for(int i = 0; i < 4; i++) {
	                int nx = x + dx[i];
	                int ny = y + dy[i];
	                if(nx >= 0 && ny >= 0 && nx < n && ny < m) {
	                    if(virusMap[nx][ny] == BLANK) {
	                        virusMap[nx][ny] = VIRUS;
	                        q.add(new Pair(nx, ny));
	                    }
	                }
	            }
	        }
	        calAnswer(virusMap);
	    }

	    
	    static void calAnswer(int virusMap[][]) {
	        int cnt = 0;
	        for(int i = 0; i < n; i++)
	            for(int j = 0; j < m; j++)
	                if(virusMap[i][j] == BLANK)
	                    ++cnt;

	        answer = Math.max(cnt, answer);
	    }   
}