[BOJ] 백준 17144-미세먼지안녕(java)

배열 이동시키는게 중요

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.StringTokenizer;
 
public class Main{
    private static int R;
    private static int C;
    private static int T;
    private static int[][] map;
    private static int downCleanerX;
    private static int upCleanerX;
    private static int result;
    private static int[] dx = { -1, 0, 1, 0 };
    private static int[] dy = { 0, 1, 0, -1 };
    private static ArrayList<Dust> list;
 
    public static void main(String[] args) throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st = new StringTokenizer(br.readLine(), " ");
        R = Integer.parseInt(st.nextToken());
        C = Integer.parseInt(st.nextToken());
        T = Integer.parseInt(st.nextToken());
        map = new int[R][C];
        downCleanerX = 0;
        upCleanerX = 0;
        list = new ArrayList<>();
        for (int i = 0; i < R; i++) {
            st = new StringTokenizer(br.readLine(), " ");
            for (int j = 0; j < C; j++) {
                map[i][j] = Integer.parseInt(st.nextToken());
                if (map[i][j] == -1) downCleanerX = i;
            }
        }
        upCleanerX = downCleanerX - 1;
        result = 0;
        process();
        System.out.println(result);
    }// end of main
 
    public static void process() {
        while (true) {
            T--;
            //확산가능한곳 찾기
            findDust();
            // 미세먼지확산
            spread();
            // 공기 청정기 작동
            cleaner();
 
            if (T == 0) {
                check();
                break;
            }
        }
    }
    private static void check() {
        for (int i = 0; i < R; i++) {
            for (int j = 0; j < C; j++) {
                if(map[i][j] > 0) result += map[i][j];
            }
        }
    }
 
    public static void findDust() {
        list = new ArrayList<Dust>();
        for (int i = 0; i < R; i++) {
            for (int j = 0; j < C; j++) {
                if(map[i][j] > 0) list.add(new Dust(i,j ,map[i][j]));
            }
        }
    }
 
    public static void cleaner() {
        for (int i = upCleanerX ; i >0 ; i--) {
            map[i][0] = map[i-1][0];
        }
        map[upCleanerX][0] = 0;
//        print();
        for (int i = 0; i < C - 1; i++) {
            map[0][i] = map[0][i + 1];
        }
//        print();
        for (int i = 0; i < upCleanerX; i++) {
            map[i][C-1] = map[i + 1][C-1];
        }
//        print();
        for (int i = C - 1; i >= 1; i--) {
            map[upCleanerX][i] = map[upCleanerX][i - 1];
        }
//        print();
        map[upCleanerX][0] = -1;
//        print();
        //아래 시계방향
        for (int i = downCleanerX; i < R-1 ; i++) {
            map[i][0] = map[i+1][0];
        }
        map[downCleanerX][0] =0;
//        print();
        for (int i = 0; i < C - 1; i++) {
            map[R-1][i] = map[R-1][i + 1];
        }
//        print();
        for (int i = R-1; i > downCleanerX; i--) {
            map[i][C-1] = map[i-1][C-1];
        }
//        print();
        for (int i = C - 1; i >= 1; i--) {
            map[downCleanerX][i] = map[downCleanerX][i - 1];
        }
//        print();
        map[downCleanerX][0] = -1;
//        print();
    }
 
    public static void spread() {
        for (Dust d : list) {
            int count = 0;
            for (int i = 0; i < dx.length; i++) {
                int nx = d.x + dx[i];
                int ny = d.y + dy[i];
                if(nx>=0 && ny>=0 && nx <R && ny <C &&map[nx][ny]>=0) {
                    count++;
                    map[nx][ny] += d.size /5; 
                }
            }
            map[d.x][d.y]= map[d.x][d.y]- (d.size/5) * count;  
//            print();
        }
    }
    public static void print() {
        for (int i = 0; i < R; i++) {
            for (int j = 0; j < C; j++) {
                System.out.print(map[i][j] + " ");
            }
            System.out.println();
        }
        
        System.out.println("==========================");
    }
 
    static class Dust {
        int x;
        int y;
        int size;
 
        public Dust(int x, int y, int size) {
            super();
            this.x = x;
            this.y = y;
            this.size = size;
        }
 
        @Override
        public String toString() {
            return "dust [x=" + x + ", y=" + y + ", size=" + size + "]";
        }
 
    }
}// end of class