무인도 여행

package programmers;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.LinkedList;
import java.util.List;
import java.util.Queue;

public class 무인도_여행 {

   private static int[] dy = {-1, 0, 1, 0};
   private static int[] dx = {0, 1, 0, -1};

   public static int[] solution(String[] maps) {
      char[][] map = init(maps);
      List<Integer> ansList = go(map);

      if (ansList.isEmpty()) {
         return new int[] {-1};
      }

      return ansList.stream()
         .mapToInt(Integer::intValue)
         .sorted()
         .toArray();
   }

   private static List<Integer> go(char[][] map) {
      List<Integer> ans = new ArrayList<>();
      boolean[][] visited = new boolean[map.length][map[0].length];

      for (int i = 0; i < map.length; i++) {
         for (int j = 0; j < map[0].length; j++) {
            if (isNumber(map[i][j]) && !visited[i][j]) {
               ans.add(bfs(i, j, map, visited));
            }
         }
      }

      return ans;
   }

   private static int bfs(int y, int x, char[][] map, boolean[][] visited) {
      int ans = map[y][x] - '0';
      Queue<Pair> q = new LinkedList<>();

      q.add(new Pair(y, x));
      visited[y][x] = true;

      while (!q.isEmpty()) {
         Pair p = q.poll();
         for (int i = 0; i < 4; i++) {
            int ny = p.y + dy[i];
            int nx = p.x + dx[i];
            if (isNotMap(ny, nx, map) || visited[ny][nx]) {
               continue;
            }

            q.add(new Pair(ny, nx));
            visited[ny][nx] = true;
            ans += map[ny][nx] - '0';
         }
      }

      return ans;
   }

   private static boolean isNotMap(int y, int x, char[][] map) {
      return y < 0 || x < 0 || y >= map.length || x >= map[0].length || map[y][x] == 'X';
   }

   private static boolean isNumber(char c) {
      return c >= '0' && c <= '9';
   }

   private static char[][] init(String[] maps) {
      char[][] map = new char[maps.length][maps[0].length()];

      for (int i = 0; i < map.length; i++) {
         String s = maps[i];
         for (int j = 0; j < map[0].length; j++) {
            map[i][j] = s.charAt(j);
         }
      }

      return map;
   }

   private static class Pair {
      int y, x;

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

   public static void main(String[] args) {
      System.out.println(Arrays.toString(solution(new String[] {"X591X", "X1X5X", "X231X", "1XXX1"})));
      System.out.println(Arrays.toString(solution(new String[] {"XXX", "XXX", "XXX"})));
   }
}