private static int ArgumentsCheck(GdcAlgorithm algorithm, params int[] numbers)
{
if (numbers.Length == 0)
{
throw new NullReferenceException();
}
if (numbers.Length == 1)
{
return(numbers[0]);
}
int gdc = 0;
if (numbers[0] > 0 && numbers[1] > 0)
{
gdc = FindGdc(numbers[0], numbers[1], algorithm);
}
else
{
throw new ArgumentOutOfRangeException();
}
for (int i = 2; i < numbers.Length - 1; i++)
{
if (numbers[i] <= 0)
{
throw new ArgumentOutOfRangeException();
}
gdc = FindGdc(gdc, numbers[i], algorithm);
}
return(gdc);
}
private static int FindGdc(int a, int b, GdcAlgorithm algorithm)
{
if (a == 0)
{
return(b);
}
if (b == 0)
{
return(a);
}
if (a == b)
{
return(a);
}
if (a % 2 == 0 && b % 2 == 0)
{
return(2 * FindGdc(algorithm(a), algorithm(b), algorithm));
}
if (a % 2 == 0)
{
return(FindGdc(algorithm(a), b, algorithm));
}
if (b % 2 == 0)
{
return(FindGdc(a, algorithm(b), algorithm));
}
if (a > b)
{
return(FindGdc(algorithm(a - b), a, algorithm));
}
if (a < b)
{
return(FindGdc(algorithm(b - a), a, algorithm));
}
return(FindGdc(a, b, algorithm));
}
public static int FindGDCbySteinsAlgorithm(params int[] numbers)
{
GdcAlgorithm algorithm = new GdcAlgorithm((x) => x >> 1);
return(ArgumentsCheck(algorithm, numbers));
}
public static int FindGDCbyEuclideanAlgorithm(params int[] numbers)
{
GdcAlgorithm algorithm = new GdcAlgorithm((x) => x / 2);
return(ArgumentsCheck(algorithm, numbers));
}