private bool AreGcdEqual(int a, int b, int c)
{
var gcd1 = _totient.GreatestCommonDivisor(a, b);
var gcd2 = _totient.GreatestCommonDivisor(a, c);
var gcd3 = _totient.GreatestCommonDivisor(b, c);
return(gcd1 == gcd2 && gcd2 == gcd3);
}
public Tuple <int, int> GetPreviousNumberBefore3Over7(int upto)
{
double comparisonValue = (double)3 / 7;
double previousValue = 0;
Tuple <int, int> previousTuple = new Tuple <int, int>(0, 0);
for (int n = 1; n < upto; n++)
{
for (int d = upto; d >= n + 1; d--)
{
double fractionValue = (double)n / d;
if (fractionValue > comparisonValue)
{
break;
}
if (previousValue > fractionValue)
{
continue;
}
if (n % d == 0 || d % n == 0)
{
continue;
}
if ((n != 3 && d != 7) && _totient.GreatestCommonDivisor(n, d) == 1)
{
previousValue = fractionValue;
previousTuple = new Tuple <int, int>(n, d);
}
}
}
return(previousTuple);
}
public void TestGreatestCommonDivisorCollectionCreation()
{
const int upto = 100;
Dictionary <Tuple <int, int>, int> lookup = new Dictionary <Tuple <int, int>, int>();
for (int i = 1; i <= upto; i++)
{
for (int j = 2; j <= upto; j++)
{
Tuple <int, int> key = new Tuple <int, int>(j, i);
//if (!lookup.ContainsKey(key))
lookup[key] = _sut.GreatestCommonDivisor(j, i);
}
}
_output.WriteLine(lookup.Keys.Count.ToString());
}
