The core of the application’s operation is a recursive method that moves a tower from one stick to another. Let’s assume that a tower consisting of n disks needs to be moved from stick 1 to stick 3. At first glance, the implementation of such a method seems complicated. However, we can use the following approach:
- Move the sub-tower consisting of the top n – 1 disks from stick 1 to stick 2,
- Move the remaining bottom disk from stick 1 to stick 3,
- Move the sub-tower temporarily placed on stick 2 to stick 3.
To move the sub-tower with n – 1 disks, we use the same approach, this time moving a sub-tower with n – 2 disks and the bottom disk.
Below is the code for the method:
private async Task Go(ushort aFromTower, ushort aToTower, ushort aTemporaryTower, ushort aDisks)
{
while (!mUserMakesGo)
{
await Task.Delay(33);
} // while
if (aDisks > 1)
{
await Go(aFromTower, aTemporaryTower, aToTower, (ushort)(aDisks – 1));
await Go(aFromTower, aToTower, aTemporaryTower, 1);
await Go(aTemporaryTower, aToTower, aFromTower, (ushort)(aDisks – 1));
}
else
{
mUserMakesGo = false;
ushort disk = mComputerTowers[aFromTower].RemoveDisk();
mComputerTowers[aFromTower].Draw();
mComputerTowers[aToTower].AddDisk(disk);
mComputerMoves++;
mSpeechText.Add($“The computer moved disk {disk} from tower {aFromTower + 1} to tower {aToTower + 1}.“);
if (mComputerTowers[2].DisksNumber == mDisks)
{
if (mUserTowers[2].DisksNumber == mDisks)
{
mSpeechText.Add(„Draw“);
await MessageDialog(„Game Over“, „Draw.“);
}
else
{
mSpeechText.Add(„The computer is the winner!“);
await MessageDialog(„Game Over“, „The computer is the winner.“);
}
Application.Current.Exit();
}
}
} // Go
The voice accompaniment and visualization of the user’s and computer’s towers are implemented by the respective classes.
