programmers_무인도 여행_java

https://school.programmers.co.kr/learn/courses/30/lessons/154540

프로그래머스

import java.util.*;

class Solution {
    
    private static int[][] delta = {{1,0}, {-1,0}, {0, 1}, {0, -1}};
    
    public int[] solution(String[] maps) {
        int[] answer = {-1};
        
        int width = maps[0].length();
        int height = maps.length;
        boolean[][] visited = new boolean[height][width];
        StringBuilder sb = new StringBuilder();
        boolean flag = false;
        for(int i =0; i<height; i++){
            for(int j = 0; j<width; j++){
                if(!visited[i][j] && maps[i].charAt(j) != 'X'){      
                    flag = true;
                    sb.append(bfs(maps, i, j, visited, width, height)).append(" ");
                }
            }
        }
        
        if(flag){
            String[] ansArr = sb.toString().split(" ");            
            answer = Arrays.stream(ansArr).mapToInt(Integer::parseInt).toArray();
            Arrays.sort(answer);
            System.out.println(answer);    
        }
        
        
        return answer;
    }
    
    private int bfs(String[] maps, int y, int x, boolean[][] visited, int width, int height){
        Queue<Point> queue = new LinkedList<>();        
        queue.offer(new Point(y, x, maps[y].charAt(x) - '0'));
        
        int days = 0;
        while(!queue.isEmpty()){
            Point now = queue.poll();
            
            if(visited[now.y][now.x] ) continue;
            visited[now.y][now.x] = true;
            days+= now.food;
            
            for(int i = 0; i<4; i++){
                int nexty = now.y + delta[i][0];
                int nextx = now.x + delta[i][1];
                if(0<= nexty && nexty <height && 0<= nextx && nextx <width && !visited[nexty][nextx] && maps[nexty].charAt(nextx) != 'X'){
                    queue.offer(new Point(nexty, nextx, maps[nexty].charAt(nextx) - '0'));
                }
            }            
        }
        
        return days;
    }
    
    private class Point{
        int y, x, food;
        public Point(int y, int x, int food){
            this.y = y;
            this.x = x;
            this.food = food;
        }
    }
}