import java.awt.*;
import java.applet.Applet;

class GoogleKnightsPanel extends Panel {

    int state[][] = new int[5][5];

    static int levels[][][] = {
	{
	    { 0, 2, 2, 2, 0 },
	    { 2, 0, 0, 0, 0 },
	    { 1, 0, 1, 1, 0 },
	    { 3, 0, 0, 3, 0 },
	    { 0, 3, 3, 0, 0 },
	},
	{
	    { 0, 2, 2, 0, 0 },
	    { 1, 0, 0, 1, 0 },
	    { 1, 0, 0, 1, 0 },
	    { 0, 3, 3, 0, 0 },
	    { 0, 0, 0, 0, 0 },
	},
	{
	    { 2, 2, 2, 0, 0 },
	    { 1, 0, 1, 0, 0 },
	    { 3, 3, 3, 0, 0 },
	    { 0, 0, 0, 0, 0 },
	    { 0, 0, 0, 0, 0 },
	},
	{
	    { 0, 2, 2, 0, 0 },
	    { 1, 0, 2, 0, 0 },
	    { 1, 1, 1, 0, 0 },
	    { 0, 0, 3, 0, 0 },
	    { 3, 3, 0, 0, 0 },
	},
	{
	    { 1, 2, 2, 0, 0 },
	    { 0, 2, 2, 0, 0 },
	    { 0, 1, 1, 0, 0 },
	    { 0, 1, 1, 0, 0 },
	    { 1, 3, 3, 3, 3 },
	},
	{
	    { 0, 2, 2, 0, 0 },
	    { 1, 0, 0, 2, 0 },
	    { 3, 1, 1, 2, 0 },
	    { 3, 0, 0, 0, 0 },
	    { 0, 3, 3, 0, 0 },
	},
    };
    
    static String answers[] = {
	"B5A3D4B5B1C3A3B1B5A3C3B5B5D4A2C3C3B5A4C3C5A4C3A2C1D3D3C5A2C1A4C3C3A2D1C3C3A4B1C3A3B1C3D1",
	"C1D3B1A3B4A2C4D2D3B4A3C4A2C1D2B1",
	"A1C2B3A1C3A2B1C3A3B1C2A3C1B3A2C1",
	"C2A3B5C3A3B5C4A3A3C2B1A3A3C4A5B3C3B1C1A2B3C1A2C3B5A3C4A5C3B5A3C4",
	"C2A1D5B4B4C2C5B3B3A5A5C4A1B3B3A5C1B3B3C5C2A1A1B3B3C1B1C3C3D5A5B3B3A1A1C2C2B4C4A5A5B3B3A1A1C2B5C3C3B1B2C4C4A5E5C4C4B2A5C4C4E5D5C3C3B5B4D5",
	"C1A2D3C1C5D3A4C5B1C3C3A4A3B1B5A3A2C3C3B5C1A2D3C1C5D3D2B3B3C5B1D2A3B1A2C3B5A3C3B5",
    };
    
    GoogleKnightsPanel() {
	//setBackground(Color.black); 
	setuppieces();
    } 
    
    int level=0, step=0;

    public void paint(Graphics g) { 
	g.setFont(new Font("Arial",Font.BOLD,18)); //set the font
	Color white = new Color(0x99, 0x99, 0xFF);
	Color black = new Color(0x66, 0x66, 0xFF);
	Color gray = new Color(0xFF, 0xFF, 0xFF);
	int r, col;
	// draw board
	for(r=0;r<5;r++) {
	    for(col=0;col<5;col++) {
		if(state[r][col] == 0) 
		    g.setColor(gray);
		else if((r+col)%2 == 1)
		    g.setColor(white);
		else
		    g.setColor(black);
		g.fillRect(col*30, r*30, 30, 30);
	    }
	}
	// draw targets
	for(r=0;r<5;r++) {
	    for(col=0;col<5;col++) {
		if(levels[level][r][col] > 1) {
		    if(levels[level][r][col] == 2) {
			g.setColor(Color.black);
		    } else {
			g.setColor(Color.white);
		    }
		    g.drawRect(col*30+5, r*30+5, 20, 20);
		}
	    }
	}
	// draw pieces
	for(r=0;r<5;r++) {
	    for(col=0;col<5;col++) {
		if(state[r][col] > 1) {
		    if(state[r][col] == 3)
			g.setColor(Color.black);
		    else
			g.setColor(Color.white);
		    g.fillOval(col*30+7, r*30+7, 17, 17);
		}
	    }
	}
    } //end of paint method

    void movepieces() {
	int i, fromr, fromc, tor, toc;
	setuppieces();
	for(i=0;i<step;i++) {
	    fromc = answers[level].charAt(i*4)-'A';
	    fromr = answers[level].charAt(i*4+1)-'1';
	    toc = answers[level].charAt(i*4+2)-'A';
	    tor = answers[level].charAt(i*4+3)-'1';
	    state[tor][toc] = state[fromr][fromc];
	    state[fromr][fromc] = 1;
	}
	repaint();
    }
    
    void setuppieces() {
	int r, c;
	for(r=0;r<5;r++)
	    for(c=0;c<5;c++)
		state[r][c]=levels[level][r][c];
    }
    
    public void nextlev() {
	level = (level+1)%6;
	step=0;
	setuppieces();
	repaint();
    }

    public void prevlev() {
	level = (level+5)%6;
	step=0;
	setuppieces();
	repaint();
    }

    public void prev() {
	step = (step+answers[level].length()/4)%(answers[level].length()/4+1);
	movepieces();
    }
    
    public void next() {
	step = (step+1)%(answers[level].length()/4+1);
	movepieces();
    }
    //	case next: panel.next(); break;
    //	case prev: panel.prev(); break;

} // end of HelloWorld 

public class GoogleKnights extends Applet {
    Button nextlev;
    Button prevlev;
    Button prev;
    Button next;
    GoogleKnightsPanel panel;
    
    public void init ( ) {
	setLayout(new GridBagLayout());
        GridBagConstraints c = new GridBagConstraints();
	c.fill = GridBagConstraints.BOTH;
	c.gridx = 0;
        c.gridy = 0;
	c.weighty=1.0;
	c.weightx=1.0;
	c.gridwidth=2;
	add(panel = new GoogleKnightsPanel(), c);
	c.weighty=0.0;
	c.gridwidth=1;
	//c.weightx=0.0;
	c.gridx = 0; c.gridy = 1;
	add(prevlev = new Button("<<"), c);
	c.gridx = 1; c.gridy = 1;
	add(nextlev = new Button(">>"), c);
	c.gridx = 0; c.gridy = 2;
	add(prev = new Button("<"), c);
	c.gridx = 1; c.gridy = 2;
	add(next = new Button(">"), c);
    }

    public boolean action (Event evt, Object what)
    {
	if(evt.target == nextlev)
	    panel.nextlev();
	else if(evt.target == prevlev)
	    panel.prevlev(); 
	else if(evt.target == next)
	    panel.next(); 
	else if(evt.target == prev)
	    panel.prev(); 
	return false;
    }

}