Main.java

class GFG
{

static int M = 3;
static int N = 3;

static void floodFillUtil(int screen[][], int x, int y, int prevC, int newC)
{
	if (x < 0 || x >= M || y < 0 || y >= N)
		return ;
	if (screen[x][y] != prevC)
		return ;

	screen[x][y] = newC;

	floodFillUtil(screen, x+1, y, prevC, newC);
	floodFillUtil(screen, x-1, y, prevC, newC);
	floodFillUtil(screen, x, y+1, prevC, newC);
	floodFillUtil(screen, x, y-1, prevC, newC);
}


static void floodFill(int screen[][], int x, int y, int newC)
{
	int prevC = screen[x][y];
	if(prevC==newC) return;
	floodFillUtil(screen, x, y, prevC, newC);
}

// Driver code
public static void main(String[] args){
	// int screen[][] = {{1, 1, 1, 1, 1, 1, 1, 1},
	// 				{1, 1, 1, 1, 1, 1, 0, 0},
	// 				{1, 0, 0, 1, 1, 0, 1, 1},
	// 				{1, 2, 2, 2, 2, 0, 1, 0},
	// 				{1, 1, 1, 2, 2, 0, 1, 0},
	// 				{1, 1, 1, 2, 2, 2, 2, 0},
	// 				{1, 1, 1, 1, 1, 2, 1, 1},
	// 				{1, 1, 1, 1, 1, 2, 2, 1},
	// 				};

    int screen[][]={
                    {1,1,1},
                    {1,2,2},
                    {1,0,1}
                    };
	int x = 4, y = 4, newC = 3;
	floodFill(screen, x, y, newC);

	System.out.println("Updated screen after call to floodFill: ");
	for (int i = 0; i < N; i++)
	{
		for (int j = 0; j < N; j++)
		System.out.print(screen[i][j] + " ");
		System.out.println();
	}
	}
}