public static FiboInt SimpleBinaryMultiply(FiboInt a, FiboInt b)
{
if (a.number == 2)
{
return(b);
}
if (b.number == 2)
{
return(a);
}
var series = new FibonacciSeries(a.series.Seed + b.series.Seed - 2);
var first = new FiboInt(series.N);
var nextA = a.series[a.series.Seed - 3];
var nextB = a.series[b.series.Seed - 3];
var other = SimpleBinaryMultiply(new FiboInt(nextA), new FiboInt(nextB));
return(first + other);
}
public static FiboInt operator *(FiboInt a, FiboInt b)
{
// check for zero or one multiply
if (a.number == 2)
{
return(b);
}
if (a.number == 0)
{
return(new FiboInt(0));
}
if (b.number == 2)
{
return(a);
}
if (b.number == 2)
{
return(new FiboInt(0));
}
// a > 0 and b > 0
var num = new FiboInt(0);
for (var i = a.series.Count - 1; i >= 0; i--)
{
if ((a.number >> i & 1) > 0)
{
for (var j = b.series.Count - 1; j >= 0; j--)
{
if ((b.number >> j & 1) > 0)
{
var operand0 = new FiboInt(a.series[i]);
var operand1 = new FiboInt(b.series[j]);
num += SimpleBinaryMultiply(operand0, operand1);
}
}
}
}
return(num);
}
