[BOJ] 백준 17144 미세먼지 안녕!

[문제]

https://www.acmicpc.net/problem/17144

 

 

[소스 코드]

import java.io.*;
import java.util.*;

public class Main {
	static int airR,airC;
	static int r,c,result;
	static int[] dr = {-1,1,0,0};
	static int[] dc = {0,0,-1,1};
	static int[][] map;
	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		StringTokenizer st = new StringTokenizer(br.readLine());
		r = Integer.parseInt(st.nextToken());
		c = Integer.parseInt(st.nextToken());
		int t = Integer.parseInt(st.nextToken());
		map = new int[r][c];
		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) {
					airR = i; airC = j;
				}
			}
		}
		while(t-->0) {
			spread();
			airMove();
		}
		count();
		System.out.println(result);
	}
	private static void spread() {
		int[][] add = new int[r][c];
		for(int i=0;i<r;i++) {
			for(int j=0;j<c;j++) {
				if(map[i][j]>0) {
					int cnt = 0;
					for(int d=0;d<4;d++) {
						int nr = i + dr[d];
						int nc = j + dc[d];
						if(nr<0 || nr>=r || nc<0 || nc>=c) continue;
						if(map[nr][nc]>=0) {
							add[nr][nc] += map[i][j] / 5;
							cnt++;
						}
					}
					add[i][j] -= map[i][j]/5*cnt;
				}
			}
		}
		for(int i=0;i<r;i++) {
			for(int j=0;j<c;j++) {
				map[i][j] += add[i][j];
			}
		}
	}
	private static void airMove() {
		for(int i=airR-2;i>0;i--) map[i][0] = map[i-1][0];
		for(int j=0;j<c-1;j++) map[0][j] = map[0][j+1];
		for(int i=0;i<airR-1;i++) map[i][c-1] = map[i+1][c-1];
		for(int j=c-1;j>1;j--) map[airR-1][j] = map[airR-1][j-1];
		map[airR-1][airC+1] = 0;
		for(int i=airR+1;i<r-1;i++) map[i][0] = map[i+1][0];
		for(int j=0;j<c-1;j++) map[r-1][j] = map[r-1][j+1];
		for(int i=r-1;i>airR;i--) map[i][c-1] = map[i-1][c-1];
		for(int j=c-1;j>airC+1;j--) map[airR][j] = map[airR][j-1];
		map[airR][airC+1] = 0; 
	}
	private static void count() {
		for(int i=0;i<r;i++) {
			for(int j=0;j<c;j++) {
				if(map[i][j]>0) {
					result += map[i][j];
				}
			}
		}
	}
}