[BOJ] 21610 마법사 상어와 비바라기 (JAVA)

https://www.acmicpc.net/problem/21610

21610번: 마법사 상어와 비바라기

구현은 재밌는데 귀찮아요

 

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.StringTokenizer;

public class Main {
	
    static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    static StringTokenizer st;
    static int N, M, d, s, result;
    static int[][] A;
    static int[] dr = {  0, -1, -1, -1,  0,  1,  1,  1 };
    static int[] dc = { -1, -1,  0,  1,  1,  1,  0, -1 };
    static boolean[][] check;
    static ArrayList<int[]> list = new ArrayList<>();
    static ArrayList<int[]> clouds = new ArrayList<>();

    public static void main(String[] args) throws Exception {

        st = new StringTokenizer(br.readLine(), " ");
        N = Integer.parseInt(st.nextToken());
        M = Integer.parseInt(st.nextToken());
        A = new int[N][N];
        for (int i = 0; i < N; i++) {
            st = new StringTokenizer(br.readLine(), " ");
            for (int j = 0; j < N; j++) {
                A[i][j] = Integer.parseInt(st.nextToken());
            }
        }
        for (int i = 0; i < M; i++) {
            st = new StringTokenizer(br.readLine(), " ");
            d = Integer.parseInt(st.nextToken()) - 1;
            s = Integer.parseInt(st.nextToken()) % N;
            list.add(new int[] { d, s });
        } // end of input

        // 첫 구름들
        clouds.add(new int[] { N - 2, 0 });
        clouds.add(new int[] { N - 2, 1 });
        clouds.add(new int[] { N - 1, 0 });
        clouds.add(new int[] { N - 1, 1 });

        for (int num = 0; num < M; num++) {

            int[] skill = list.get(num);

            // 이동
            for (int i = 0; i < clouds.size(); i++) {
                int[] cloud = clouds.get(i);
                for (int j = 0; j < skill[1]; j++) {
                    cloud[0] += dr[skill[0]];
                    cloud[1] += dc[skill[0]];
                    cloud[0] = cloud[0] < 0 ? cloud[0] + N : cloud[0] % N;
                    cloud[1] = cloud[1] < 0 ? cloud[1] + N : cloud[1] % N;
                }
                clouds.set(i, cloud);
            }

            // 구름 있는 칸에 비 1씩 내림
            for (int[] cloud : clouds) {
                A[cloud[0]][cloud[1]]++;
            }

            // 대각선 물 흡수
            int[] w = new int[clouds.size()];
            for (int i = 0; i < clouds.size(); i++) {
                int[] cloud = clouds.get(i);
                for (int dir = 1; dir < 8; dir += 2) {
                    int nr = cloud[0] + dr[dir];
                    int nc = cloud[1] + dc[dir];
                    if (0 <= nr && nr < N && 0 <= nc && nc < N && 0 < A[nr][nc]) w[i]++;
                }
            }
            for (int i = 0; i < clouds.size(); i++) {
                int[] cloud = clouds.get(i);
                A[cloud[0]][cloud[1]] += w[i];
            }

            // 구름 생기고 물 제거
            check = new boolean[N][N];
            for (int[] cloud : clouds) {
                check[cloud[0]][cloud[1]] = true;
            }
            clouds.clear();
            for (int i = 0; i < N; i++) {
                for (int j = 0; j < N; j++) {
                    if (!check[i][j] && 2 <= A[i][j]) {
                        clouds.add(new int[] { i, j });
                        A[i][j] -= 2;
                    }
                }
            }

        }

        // 남아있는 물 셈
        for (int i = 0; i < N; i++) {
            for (int j = 0; j < N; j++) {
                result += A[i][j];
            }
        }

        System.out.print(result);

    }
	
}