[백준 15683, Java] 감시

package october2020;

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

class CCTV{
	int x;
	int y;
	int type;
	
	static int[] d = {4,2,4,4,1}; // type에 따라 회전 할 수 있는 경우의 수 
	
	CCTV(int x, int y, int type){
		this.x =x;
		this.y =y;
		this.type = type;
	}
	
	public String toString() {
		return "x:"+x+",y:"+y+",type:"+type;
	}
}

public class DetectionDemo {
	
	public static int[][] map;
	public static int[][] backup;
	public static int N;
	public static int M;
	public static int BLANK = 0;
	public static int WALL =6;
	
	public static ArrayList<CCTV> cctvList;
	public static int[] dx = {-1,0,1,0};
	public static int[] dy = {0,1,0,-1};
	
	public static int minCount =987654321;
	
	public static void main(String[] args) throws Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
		StringTokenizer st;
		
		st = new StringTokenizer(br.readLine(), " ");
		N = Integer.parseInt(st.nextToken());
		M = Integer.parseInt(st.nextToken());
		map = new int[N][M]; 
		backup = new int[N][M];
		
		
		cctvList = new ArrayList<CCTV>();
		for(int r = 0; r<N ; r++) {
			st = new StringTokenizer(br.readLine()," ");
			for(int c=0; c<M; c++) {
				int value = Integer.parseInt(st.nextToken());
				
				map[r][c] = value;
 				if(value!=WALL && value!=BLANK) {
					cctvList.add(new CCTV(r,c,value-1));
				}
			}
		}
		
		System.out.println(cctvList);
		
		findCCTV(0);
		bw.write(String.valueOf(minCount));
		bw.flush();
		
	}
	
	//cctvList에 있는 cctv에 대해서 모든 경우의수 탐색
	public static void findCCTV(int index) {
		if(index>=cctvList.size()) {
			
			printMap();
			System.out.println("===========================");
			minCount=Math.min(countBlank(),minCount);
			
		}
		else {
			copyMap(map, backup);
			
			CCTV cctv = cctvList.get(index);
			int cx = cctv.x;
			int cy = cctv.y;
			int type = cctv.type;
			
			for(int direction=0;direction<CCTV.d[type];direction++) {
				if(type==0) {
					detect(direction,cx,cy);
				}
				else if(type==1) {
					detect(direction,cx,cy);
					detect(direction+2,cx,cy);
				}
				else if(type ==2) {
					detect(direction,cx,cy);
					detect(direction+1,cx,cy);
				}
				else if(type ==3) {
					detect(direction,cx,cy);
					detect(direction+1,cx,cy);
					detect(direction+2,cx,cy);
					
				}
				else if(type ==4) {
					detect(direction,cx,cy);
					detect(direction+1,cx,cy);
					detect(direction+2,cx,cy);
					detect(direction+3,cx,cy);
				}
				System.out.println("----------------");
				printMap();
				System.out.println("----------------");
				findCCTV(index+1);
				copyMap(backup,map);
			}
			
			
		}
	}
	public static void detect(int direction, int x, int y) {
		direction = direction%4;
		
		if(direction ==0) {
			int tempX = x+dx[direction];
			while(tempX>=0 && map[tempX][y]!=WALL) {
				map[tempX--][y] =7;
			}
		}
		else if(direction ==1) {
			int tempY = y+dy[direction];
			while(tempY<M && map[x][tempY]!=WALL) {
				map[x][tempY++] =7;
			}
		}
		else if(direction ==2) {
			int tempX = x+dx[direction];
			while(tempX<N && map[tempX][y]!=WALL) {
				map[tempX++][y] =7;
			}
		}
		else if( direction ==3) {
			int tempY = y+dy[direction];
			while(tempY>=0 && map[x][tempY]!=WALL) {
				map[x][tempY--] =7;
			}
		}
	}
	public static void copyMap(int[][] source, int[][] dest) {
		for(int r =0 ;r<N ; r++) {
			for(int c=0;c<M;c++) {
				dest[r][c] = source[r][c];
			}
		}
	}
	public static int countBlank() {
		int result = 0;
		for(int r=0;r<N;r++) {
			for(int c=0; c<M; c++) {
				if(map[r][c]==BLANK) {
					result++;
				}
			}
		}
		
		return result;
		
	}
	
	public static void printMap() {
		for(int r=0;r<N;r++) {
			for(int c=0;c<M; c++) {
				System.out.print(map[r][c]+" ");
			}
			System.out.println();
		}
	}
}