public void TestCompareTo()
{
var r = new RandomGenerator();
for (var i = 0; i < 500; ++i)
{
ERational bigintA = RandomObjects.RandomERational(r);
ERational bigintB = RandomObjects.RandomERational(r);
ERational bigintC = RandomObjects.RandomERational(r);
TestCommon.CompareTestRelations(bigintA, bigintB, bigintC);
}
TestCommon.CompareTestLess(ERational.Zero, ERational.NaN);
ERational rat, rat2;
for (var i = 0; i < 100; ++i)
{
EInteger num = RandomObjects.RandomEInteger(r);
if (num.IsZero)
{
// Skip if number is 0; 0/1 and 0/2 are
// equal in that case
continue;
}
num = num.Abs();
rat = ERational.Create(num, EInteger.One);
rat2 = ERational.Create(num, (EInteger)2);
TestCommon.CompareTestLess(rat2, rat);
TestCommon.CompareTestGreater(rat, rat2);
}
TestCommon.CompareTestLess(
ERational.Create(EInteger.One, (EInteger)2),
ERational.Create((EInteger)4, EInteger.One));
for (var i = 0; i < 100; ++i)
{
EInteger num = RandomObjects.RandomEInteger(r);
EInteger den = RandomObjects.RandomEInteger(r);
if (den.IsZero)
{
den = EInteger.One;
}
rat = ERational.Create(num, den);
for (int j = 0; j < 10; ++j)
{
EInteger num2 = num;
EInteger den2 = den;
EInteger mult = RandomObjects.RandomEInteger(r);
if (mult.IsZero || mult.Equals(EInteger.One))
{
mult = (EInteger)2;
}
num2 *= (EInteger)mult;
den2 *= (EInteger)mult;
rat2 = ERational.Create(num2, den2);
TestCommon.CompareTestEqual(rat, rat2);
}
}
}
/// <summary>
/// Finds greatest common divisor (with Euler's algorithm)
/// </summary>
/// <param name="a">
/// First number
/// </param>
/// <param name="b">
/// Second number
/// </param>
/// <returns>
/// Returns such c that all are true
/// a | c
/// b | c
/// !∃ d > c,
/// a | d
/// b | d
/// </returns>
private static EInteger _GCD(EInteger a, EInteger b)
{
a = a.Abs();
b = b.Abs();
while (a * b > 0)
{
if (a > b)
{
a %= b;
}
else
{
b %= a;
}
}
return(a == EInteger.Zero ? b : a);
}
/// <summary>
/// <a href="https://en.wikipedia.org/wiki/Least_common_multiple#Using_the_greatest_common_divisor"/>
/// </summary>
public static EInteger Lcm(this EInteger bigintFirst, EInteger bigintSecond) =>
bigintFirst.IsZero && bigintSecond.IsZero
? EInteger.Zero
: bigintFirst.Abs().Divide(bigintFirst.Gcd(bigintSecond)).Multiply(bigintSecond.Abs());
