무인도 여행 (연습문제)

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

프로그래머스

 

풀이

import java.util.ArrayList;
import java.util.List;

class Solution {
    public Integer[] solution(String[] maps) {
        List<Integer> answer = new ArrayList<>();
        char[][] map = new char[maps.length][maps[0].length()];

        for (int i = 0; i < map.length; i++) {
            map[i] = maps[i].toCharArray();
        }

        boolean[][] visited = new boolean[map.length][map[0].length];

        for (int i = 0; i < visited.length; i++) {
            for (int j = 0; j < visited[i].length; j++) {
                if (!visited[i][j] && map[i][j] != 'X') {
                    int sum = getSum(map, visited, i, j);

                    answer.add(sum);
                }
            }
        }

        answer.sort(null);

        return answer.isEmpty() ? new Integer[]{-1} : answer.toArray(new Integer[0]);
    }

    public static int getSum(char[][] map, boolean[][] visited, int i, int j) {
        visited[i][j] = true;
        int sum = Integer.parseInt(String.valueOf(map[i][j]));

        if (i - 1 >= 0 && i - 1 < visited.length && j >= 0 && j < visited[0].length) {
            if (!visited[i - 1][j] && map[i - 1][j] != 'X') {
                sum += getSum(map, visited, i - 1, j);
            }
        }

        if (i + 1 >= 0 && i + 1 < visited.length && j >= 0 && j < visited[0].length) {
            if (!visited[i + 1][j] && map[i + 1][j] != 'X') {
                sum += getSum(map, visited, i + 1, j);
            }
        }

        if (i >= 0 && i < visited.length && j + 1 >= 0 && j + 1 < visited[0].length) {
            if (!visited[i][j + 1] && map[i][j + 1] != 'X') {
                sum += getSum(map, visited, i, j + 1);
            }
        }

        if (i >= 0 && i < visited.length && j - 1 >= 0 && j - 1 < visited[0].length) {
            if (!visited[i][j - 1] && map[i][j - 1] != 'X') {
                sum += getSum(map, visited, i, j - 1);
            }
        }

        return sum;
    }
}