Career cup 9.7

FillScreen.java

package Chapter9;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.Random;

public class FillScreen {
    private enum Direction {
	None, Left, Right, Top, Bottom
    }

    public static void fill(char[][] screen, int x, int y, char oldColor,
	    char newColor, Direction from) {
	if (x < 0 || x > screen.length - 1 || y < 0 || y > screen[0].length - 1
		|| screen[x][y] != oldColor)
	    return;

	// set current point color
	screen[x][y] = newColor;

	// left
	if (y > 0 && from != Direction.Left)
	    fill(screen, x, y - 1, oldColor, newColor, Direction.Right);

	// right
	if (y < screen[0].length - 1 && from != Direction.Right)
	    fill(screen, x, y + 1, oldColor, newColor, Direction.Left);

	// top
	if (x > 0 && from != Direction.Top)
	    fill(screen, x - 1, y, oldColor, newColor, Direction.Bottom);

	// bottom
	if (x < screen.length - 1 && from != Direction.Bottom)
	    fill(screen, x + 1, y, oldColor, newColor, Direction.Top);
    }

    private static void showScreen(char[][] screen) {
	System.out.println("Current screen:");
	for (char[] row : screen) {
	    for (char c : row) {
		System.out.print("[" + c + "] ");
	    }
	    System.out.println();
	}
	System.out.println();
    }

    public static void main(String[] args) {
	char[][] screen = new char[6][8];
	char[] ColorSet = new char[] { 'R', 'G', 'B' };
	Random r = new Random();
	for (int i = 0; i < screen.length; i++)
	    for (int j = 0; j < screen[0].length; j++)
		screen[i][j] = ColorSet[Math.abs(r.nextInt()) % ColorSet.length];
	showScreen(screen);
	
	try {
	    BufferedReader br = new BufferedReader(new InputStreamReader(
		    System.in));
	    while (true) {
		System.out.print("Enter the x axis, y axis and new color: ");
		String[] data = br.readLine().split(" ");
		int x = Integer.parseInt(data[0]);
		int y = Integer.parseInt(data[1]);
		char c = data[2].charAt(0);
		fill(screen, x, y, screen[x][y], c, Direction.None);
		showScreen(screen);
	    }
	} catch (Exception e) {
	    e.printStackTrace();
	}
    }
}