1. For the code under comment 2, use numDisks as the disk number to move. Upload your zipped assignment folder, which contains the java and class files import javax.swing.JOptionPane; import javax.swing.JFrame; import java.awt.Graphics; public class HanoiClient extends JFrame { private TowersOfHanoi tOfH; boolean started = false; public HanoiClient() { tOfH = new TowersOfHanoi(4); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); setSize(500, 300); setVisible(true); } public TowersOfHanoi getTOfH() { return tOfH; } public void setStarted(boolean b) { started = b; } public void recursiveTOfH(int numDisks, int fromTower, int toTower, int useTower) { // ***** Student writes the body of this method ***** // // Using recursion, transfer numDisks disks from the tower // fromTower to the tower toTower using the tower // useTower // The disks are numbered as follows: if we started with n disks, // the disk at the top is disk # 1 // and the disk at the bottom is disk # n // We call the moveDisk method inside the body of this method // The moveDisk method moves one disk and takes 3 arguments: // an int, representing the disk number to be moved // an int, representing the tower to move the disk from // an int, representing the tower to move the disk to // So if these three variables are: // diskNumber, fromTower, and toTower // then the call to moveDisks will be: // moveDisk(diskNumber, fromTower, toTower); if (numDisks > 0) { // Student code starts here: // 1. Move (numDisks - 1) disks from fromTower // to useTower using toTower // 2. Move one disk from fromTower to toTower // Print a message to the screen, then // call moveDisk in order to animate. // 3. Move (numDisks - 1) disks from useTower to toTower // using fromTower } // Base case: 0 disks to move ==> do nothing // // Student code ends here. } public void moveDisk(int diskNumber, int fromTower, int toTower) { repaint(); try { Thread.sleep(1000); // wait for the animation to finish } catch (Exception e) { } // update parameters tOfH.updateTowers(diskNumber, fromTower, toTower); } public void paint(Graphics g) { if (started) { super.paint(g); tOfH.draw(g); } } public int getNumberOfDisks() { boolean goodInput = false; int numberDisks = 4; // will be reassigned - default is 4 while (!goodInput) { try { String answer = JOptionPane.showInputDialog(null, "Enter number of disks between 1 and 9"); if (answer != null) { numberDisks = Integer.parseInt(answer); goodInput = true; } else { System.exit(0); } } catch (Exception e) { } } return numberDisks; } public static void main(String[] args) { HanoiClient app = new HanoiClient(); // ask user for number of disks while (true) { int numDisks = app.getNumberOfDisks(); (app.getTOfH()).setDisks(numDisks); app.setStarted(true); // start app.recursiveTOfH((app.getTOfH()).getDisks(), 0, 2, 1); // finish last step in animation app.repaint(); System.out.println("Done "); // done try { Thread.sleep(5000); // wait for the animation to finish } catch (Exception e) { } JOptionPane.showMessageDialog(null, "Done"); } } } import javax.swing.JFrame; import java.awt.Graphics; import java.awt.Color; import java.util.ArrayList; public class TowersOfHanoi { // constants for Towers' parameters private static final int TOWER_LENGTH = 200; // x coordinates of towers private static final int XT1 = 100; private static final int XT2 = 250; private static final int XT3 = 400; // y coordinate of the top of the towers private static final int YT = 250; // height of the disks private static final int HD = 15; // coefficient of expansion for the width of the disks private static final int WDC = 15; // int array representing the disks on the tower int [][] towers; // int array representing the top disk in each tower int [] top; // Number of disks private int disks; public TowersOfHanoi( int d ) { setDisks( d ); } public void setTowers( int [][] t ) { towers = t; } public int [][] getTowers( ) { return towers; } public void setTop( int [] t ) { top = t; } public int [] getTop( ) { return top; } public void setDisks( int d ) { if ( d >= 1 && d <= 9 ) disks = d; else disks = 4; towers = new int[3][disks]; // put all disks inside tower 1 to start for ( int i = 0; i < disks; i++ ) towers[0][i] = disks - i; top = new int[3]; top[0] = disks - 1; // index of top disk on tower 0 top[1] = -1; // index of top disk on tower 1 top[2] = -1; // index of top disk on tower 2 } public int getDisks( ) { return disks; } public void printMe( ) { System.out.println( "Tower 0" ); for ( int i = 0 ; i <= top[0]; i++ ) System.out.print( towers[0][i] + " " ); System.out.println( "\ttop = " + top[0] ); System.out.println( "Tower 1" ); for ( int i = 0 ; i <= top[1]; i++ ) System.out.print( towers[1][i] + " " ); System.out.println( "\ttop = " + top[1] ); System.out.println( "Tower 2" ); for ( int i = 0 ; i <= top[2]; i++ ) System.out.print( towers[2][i] + " " ); System.out.println( "\ttop = " + top[2] ); System.out.println( ); } public void updateTowers( int diskNumber, int fromTower, int toTower ) { if ( enforceRules( diskNumber, fromTower, toTower ) ) { // update toTower towers[toTower][top[toTower] + 1] = diskNumber; top[toTower] = top[toTower] + 1; // update fromTower towers[fromTower][top[fromTower]] = 0; top[fromTower] = top[fromTower] - 1; } else { System.out.println( "Illegal Move: action cancelled" ); } } public boolean enforceRules( int diskNumber, int fromTower, int toTower ) { boolean rule = true; if ( fromTower < 0 || fromTower > 2 ) rule = false; else if ( toTower < 0 || toTower > 2 ) rule = false; else if ( fromTower == toTower ) { rule = false; System.out.println( "Trying to move a disk within one tower" ); } else if ( top[fromTower] == -1 ) // fromTower empty { rule = false; System.out.println( "Trying to move a disk from tower " + fromTower + " which is empty" ); } else if ( top[toTower] == ( disks - 1 ) ) // toTower full { rule = false; System.out.println( "Trying to move a disk to tower " + toTower + " which is full" ); } else if ( top[toTower] != - 1 && diskNumber != towers[fromTower][top[fromTower]] ) // not correct disk { rule = false; System.out.println( "Trying to move a disk which is not at the top of its tower" ); } else if ( top[toTower] != -1 && towers[toTower][top[toTower]] != 0 && diskNumber > towers[toTower][top[toTower]] ) // big disk on top of small disk { rule = false; System.out.println( "Trying to place a disk on top of a smaller disk" ); } else if ( towers[fromTower][top[fromTower]] != diskNumber ) { rule = false; System.out.println( "Trying to move a disk not on top of a tower" ); } return rule; } public void draw( Graphics g ) { g.setColor( Color.BLUE ); // display tower 1 g.drawLine( XT1, YT + HD, XT1, YT - TOWER_LENGTH ); // display tower 2 g.drawLine( XT2, YT + HD, XT2, YT - TOWER_LENGTH ); // display tower 3 g.drawLine( XT3, YT + HD, XT3, YT - TOWER_LENGTH ); // display tower numbers g.drawString( "0", XT1 - 3, YT + 35 ); g.drawString( "1", XT2 - 3, YT + 35 ); g.drawString( "2", XT3 - 3, YT + 35 ); // display disks on tower 1 for ( int i = 0; i <= top[0]; i++ ) { g.setColor( Color.RED ); g.fillRoundRect( XT1 - ( WDC * towers[0][i] )/2 ,YT - i * ( HD + 2 ), WDC * towers[0][i], HD, 10, 10 ); g.setColor( Color.BLACK ); g.drawString( "" + towers[0][i], XT1 - 3, YT - i * ( HD + 2 ) + 3 * HD / 4 ); } // display disks on tower 2 for ( int i = 0; i <= top[1]; i++ ) { g.setColor( Color.RED ); g.fillRoundRect( XT2 - ( WDC * towers[1][i] )/2 ,YT - i * ( HD + 2 ), WDC * towers[1][i], HD, 10, 10 ); g.setColor( Color.BLACK ); g.drawString( "" + towers[1][i], XT2 - 3, YT - i * ( HD + 2 ) + 3 * HD / 4 ); } // display disks on tower 3 for ( int i = 0; i <= top[2]; i++ ) { g.setColor( Color.RED ); g.fillRoundRect( XT3 - ( WDC * towers[2][i] )/2 ,YT - i * ( HD + 2 ), WDC * towers[2][i], HD, 10, 10 ); g.setColor( Color.BLACK ); g.drawString( "" + towers[2][i], XT3 - 3, YT - i * ( HD + 2 ) + 3 * HD / 4 ); } } }