private AckResult Ackermann(BigInteger m, BigInteger n, BackgroundWorker bckg_work, DoWorkEventArgs e)
{
var stack = new OverflowlessStack <BigInteger>();
stack.Push(m);
while (!stack.IsEmpty)
{
m = stack.Pop();
skipStack:
if (bckg_work.CancellationPending)
{
e.Cancel = true;
stack = new OverflowlessStack <BigInteger>();
GC.Collect();
break;
}
if (m == 0)
{
n = n + 1;
}
else if (m == 1)
{
n = n + 2;
}
else if (m == 2)
{
n = n * 2 + 3;
}
else if (n == 0)
{
--m;
n = 1;
goto skipStack;
}
else
{
stack.Push(m - 1);
--n;
goto skipStack;
}
}
return(new AckResult {
result = n
});
}
public static BigInteger Ackermann(BigInteger m, BigInteger n)
{
var stack = new OverflowlessStack <BigInteger>();
stack.Push(m);
while (!stack.IsEmpty)
{
m = stack.Pop();
skipStack:
if (m == 0)
{
n = n + 1;
}
else if (m == 1)
{
n = n + 2;
}
else if (m == 2)
{
n = n * 2 + 3;
}
else if (n == 0)
{
--m;
n = 1;
goto skipStack;
}
else
{
stack.Push(m - 1);
--n;
goto skipStack;
}
}
return(n);
}