public void LeastCommonMultiple_Long(long x, long y, long lcm)
{
long actual = EuclideanAlgorithm.LeastCommonMultiple(x, y);
Assert.Equal(lcm, actual);
}
public void LeastCommonMultiple_Int(int x, int y, int lcm)
{
int actual = EuclideanAlgorithm.LeastCommonMultiple(x, y);
Assert.Equal(lcm, actual);
}
public void GreatestCommonDivisor_Int(int x, int y, int gcd)
{
int actual = EuclideanAlgorithm.GreatestCommonDivisor(x, y);
Assert.Equal(gcd, actual);
}
public void GreatestCommonDivisor_Long(long x, long y, long gcd)
{
long actual = EuclideanAlgorithm.GreatestCommonDivisor(x, y);
Assert.Equal(gcd, actual);
}
public static Rational64 Multiply(Rational64 first, Rational64 second)
{
unchecked {
var first_numerator = (UInt32)first.bits;
var first_denominator = (Int32)(first.bits >> 32);
var second_numerator = (UInt32)second.bits;
var second_denominator = (Int32)(second.bits >> 32);
if (0 == first_numerator || 0 == second_numerator)
{
return(Zero);
}
var s = 0 > (first_denominator ^ second_denominator);
if (0 <= first_denominator)
{
++first_denominator;
}
else
{
first_denominator = -first_denominator;
}
if (0 <= second_denominator)
{
++second_denominator;
}
else
{
second_denominator = -second_denominator;
}
{
var d = EuclideanAlgorithm.GreatestCommonDivisorPartial((UInt32)first_denominator, second_numerator);
first_denominator = (Int32)((UInt32)first_denominator / d);
second_numerator /= d;
}
{
var d = EuclideanAlgorithm.GreatestCommonDivisorPartial(first_numerator, (UInt32)second_denominator);
first_numerator /= d;
second_denominator = (Int32)((UInt32)second_denominator / d);
}
/*
* var q = (Int64)((UInt64)(UInt32)first_denominator * (UInt32)second_denominator);
* if (s) {
* q = -q;
* } else {
* --q;
* }
* checked((Int32)q).Ignore();
* return new Rational64(checked(first_numerator * second_numerator) | (UInt64)q << 32);
*/
var p = (UInt64)first_numerator * second_numerator;
var q = (Int64)((UInt64)(UInt32)first_denominator * (UInt32)second_denominator);
p = checked ((UInt32)p);
checked (unchecked ((UInt32)Int32.MinValue) - unchecked ((UInt64)q)).Ignore();
if (s)
{
return(new Rational64((UInt64)(-q << 32) | p));
}
else
{
return(new Rational64((UInt64)(--q << 32) | p));
}
}
}
