// Move the nth disk of the first tower
public void MoveDiskFromFirstTowerToLast(int n)
{
if (first == null || n == 0)
{
return;
}
// Pop the disks that's smaller than n in the 1st stack
List <int> firstDisks = PopDisksFromtheStackAboveDiskN(first, n);
// Get disk N from the 1st stack
int diskN = first.pop();
// Put the disks back into the 1st stack
PushDisksBackTotheStack(first, firstDisks);
if (second != null)
{
// Insert diskN to the 2nd stack
List <int> secDisks = InsertDiskIntoAStack(second, diskN, false);
// Put the disks back into the 2nd stack
PushDisksBackTotheStack(second, secDisks);
}
if (third == null)
{
third = new StackOfDisks();
}
// Insert diskN to the 3rd stack
List <int> thdDisks = InsertDiskIntoAStack(third, diskN, true);
// Put the disks back into the 3rd stack
PushDisksBackTotheStack(third, thdDisks);
}
public List <int> InsertDiskIntoAStack(StackOfDisks s, int diamterOfDisk, bool putdown)
{
List <int> disks = new List <int>();
while (true)
{
int d = s.pop();
if (d < diamterOfDisk)
{
disks.Add(d);
}
else
{
s.push(d); // Put the bigger disk back to stack
if (putdown)
{
s.push(diamterOfDisk); // put the diskN to the stack
}
break;
}
}
return(disks);
}