Counting Cells in Blob(Blob 셀 수 세기)

재귀를 이용하여 구현하였다.

 

public class Main {
	//이차원 배열로 이미지 표현
	static int arr[][] ={
				{1,0,0,0,0,0,0,1},
				{0,1,1,0,0,1,0,0},
				{1,1,0,0,1,0,1,0},
				{0,0,0,0,0,1,0,0},
				{0,1,0,1,0,1,0,0},
				{0,1,0,1,0,1,0,0},
				{1,0,0,0,1,0,0,1},
				{0,1,1,0,0,1,1,1}};
	
    //상수로 컬러 표현
	public static final int BackgroundColor = 0;
	public static final int ImageColor = 1;
	public static final int AlreadyCounted = 2;
	
	public static void main(String[] args){
		
		System.out.println(countBlob(7,7));
        
	}

    //재귀적으로 구현
    static int countBlob(int x, int y) {
    	
    	if(x<0 || y<0 || x>7 || y>7)
    		return 0;
    	if(arr[x][y]==BackgroundColor || arr[x][y]==AlreadyCounted)
    		return 0;
    	
    	int count = 1;
    	arr[x][y] = AlreadyCounted;
    	for(int i=x-1; i<=x+1; i++)
    		for(int j=y-1; j<=y+1; j++) {
    			if(i==x&&y==j) continue;
    			count+=countBlob(i, j);
    		}
    	
    	return count;
    }
}