programmers_카카오프렌즈 컬러링북_java

https://school.programmers.co.kr/learn/courses/30/lessons/1829

프로그래머스

import java.util.*;

class Solution {
    
    public static int[][] delta = {{-1, 0}, {1, 0}, {0, -1}, {0, 1}}; //상 하 좌 우

    public int[] solution(int m, int n, int[][] picture) {
        int numberOfArea = 0;
        int maxSizeOfOneArea = 0;

        boolean[][] visited = new boolean[m][n];
        for (int i = 0; i<m; i++){
            for (int j = 0; j<n; j++){
                if (!visited[i][j] && picture[i][j] != 0){
                    numberOfArea++;
                    maxSizeOfOneArea = Math.max(maxSizeOfOneArea, findArea(m, n, picture, i, j, visited));
                }
            }
        }

        int[] answer = new int[2];
        answer[0] = numberOfArea;
        answer[1] = maxSizeOfOneArea;
        return answer;
    }

    public int findArea(int m, int n, int[][] picture, int y, int x, boolean[][] visited){
        Queue<int[]> queue = new LinkedList<>();
        queue.offer(new int[]{y, x});
        int cnt = 0;

        while (!queue.isEmpty()){
            int[] now = queue.poll();

            if (visited[now[0]][now[1]]) continue;
            visited[now[0]][now[1]] = true;
            cnt++;

            for (int i = 0; i< 4; i++){
                int nexty = now[0] + delta[i][0];
                int nextx = now[1] + delta[i][1];

                if (0<= nexty && nexty < m
                        && 0<= nextx && nextx < n
                        && !visited[nexty][nextx]
                        && picture[nexty][nextx] == picture[now[0]][now[1]]
                ){
                    queue.offer(new int[]{nexty, nextx});
                }
            }
        }

        return cnt;
    }
}