public static Rational FromString(string rational)
{
Rational result;
if (Regex.Match(rational, @"^[+-]?\d+\/\d+").Value == rational)
{
var numerator = int.Parse(rational.Substring(0, rational.LastIndexOf('/')));
var denominator = int.Parse(rational.Substring(rational.LastIndexOf('/') + 1));
result = Simplify(numerator, denominator);
}
else if (Regex.Match(rational, @"^[+-]?\d+(\.\d+)?").Value == rational)
{
if (rational.LastIndexOf('.') == -1)
{
result = new Rational(int.Parse(rational));
}
else
{
result = FromDouble(double.Parse(rational));
}
}
else
{
throw new RationalException("Cadena invalida", new FormatException(rational + " not valid."));
}
return result;
}
public static bool Eq(this Rational a, Rational b)
{
bool areEquals = !AreNullOperands(a, b) &&
(a.Sub(b).Numerator == 0 || Rational.ReferenceEquals(a, b));
return areEquals;
}
public static Rational Add(this Rational a, Rational b)
{
AssertNotNullOperand(a);
AssertNotNullOperand(b);
var resultNumerator = (a.Sign * a.Numerator * b.Denominator) + (b.Sign * b.Numerator * a.Denominator);
var resultDenominator = a.Denominator * b.Denominator;
return new Rational(resultNumerator, resultDenominator);
}
public static Rational Mul(this Rational a, Rational b)
{
AssertNotNullOperand(a);
AssertNotNullOperand(b);
var resultNumerator = a.Numerator * b.Numerator;
var resultDenominator = a.Denominator * b.Denominator;
var resultSign = a.Sign * b.Sign;
return new Rational(resultNumerator, resultDenominator, resultSign);
}
public static string ToString(Rational rational)
{
var displayValue = "0";
if (rational.Numerator != 0)
{
displayValue = (rational.Sign != 1 ? "-" : string.Empty)
+ rational.Numerator
+ (rational.Denominator != 1 ? "/" + rational.Denominator : string.Empty);
}
return displayValue;
}
public static bool Gt(this Rational a, Rational b)
{
bool isGreaterThan = false;
if (!AreNullOperands(a, b))
{
var diff = a.Sub(b);
isGreaterThan = diff.Numerator != 0 && diff.Sign > 0;
}
return isGreaterThan;
}
public static Rational FromDouble(double rational)
{
Rational result;
if (rational - Math.Truncate(rational) != 0)
{
var pow = 1;
var decimalCount = rational.ToString().Substring(rational.ToString().LastIndexOf('.') + 1).Length;
for (int i = 0; i < decimalCount; i++)
{
pow *= 10;
}
result = Simplify((int)(rational * pow), pow);
}
else
{
result = new Rational((int)rational);
}
return result;
}
private static bool AreNullOperands(this Rational a, Rational b)
{
return ((object)a == null) || ((object)b == null);
}
public static Rational Sub(this Rational a, Rational b)
{
var inverseAditive = b.Mul(new Rational(-1));
return a.Add(inverseAditive);
}
public static bool Ne(this Rational a, Rational b)
{
return !a.Eq(b);
}
public static bool Lt(this Rational a, Rational b)
{
return b.Gt(a);
}
public static bool Le(this Rational a, Rational b)
{
return b.Ge(a);
}
public static bool Ge(this Rational a, Rational b)
{
return a.Gt(b) || a.Eq(b);
}
public static Rational Div(this Rational a, Rational b)
{
var inverseMultiplicative = new Rational(b.Denominator, b.Numerator, b.Sign);
return a.Mul(inverseMultiplicative);
}