char FindCommonDigit(Fraction fraction)
{
foreach (var c in fraction.Numerator.ToString()) {
if (fraction.Denominator.ToString().Contains(c)) return c;
}
return char.MinValue;
}
Fraction RemoveCommonDigits(Fraction fraction)
{
var commonDigit = FindCommonDigit(fraction);
var regex = new Regex(commonDigit.ToString());
var modifiedNumerator = regex.Replace(fraction.Numerator.ToString(), string.Empty, 1);
var modifiedDenominator = regex.Replace(fraction.Denominator.ToString(), string.Empty, 1);
return new Fraction(int.Parse(modifiedNumerator), int.Parse(modifiedDenominator));
}
Fraction Calculate(Stack<double> s)
{
Fraction result = new Fraction { H = "0", K = "1" };
foreach(double i in s)
{
if (result.H == "0")
result = new Fraction { H = i.ToString(), K = "1" };
else
result = new Fraction
{
H = Common.AddLargeInt(Common.MultiplyLargeInt(result.H, i.ToString()), result.K),
K = result.H
};
}
return result;
}
public override long Solve()
{
var curiousFractions = new List<Fraction>();
for (int numerator = 11; numerator < 99; numerator++) {
for (int denominator = numerator + 1; denominator < 100; denominator++) {
var fraction = new Fraction(numerator, denominator);
if (fraction.HasCommonDigits() && !IsTrivial(fraction)) {
var fractionWithCommonDigitsRemoved = RemoveCommonDigits(fraction);
if (fraction.CanBeReducedTo(fractionWithCommonDigitsRemoved)) {
curiousFractions.Add(fraction);
}
}
}
}
var productOfFractions = curiousFractions.Aggregate((product, nextFraction) => product * nextFraction);
var reduced = productOfFractions.Reduce();
return reduced.Denominator;
}
internal RootForm(int n)
{
int r = 1;
while (r * r <= n)
r++;
r--;
int d = n - r * r;
if (d == 0)
return;
int a = 1;
while ((r - d * a) * (r - d * a) < n)
a++;
a--;
Fraction f = new Fraction { Up = d * a - r, Down = d };
while (true)
{
if (_period.Contains(f))
return;
_period.Add(f);
f = f.Next(n);
}
}
private bool DoesNumeratorHaveMoreDigits(Fraction num)
{
return(GetDigitCount(num.Numerator) > GetDigitCount(num.Denominator));
}
private bool IsTrivial(Fraction fraction)
{
return fraction.Numerator % 10 == 0 || fraction.Denominator % 10 == 0;
}
public bool CanBeReducedTo(Fraction fraction)
{
if (numerator == 0 || denominator == 0 || fraction.Numerator == 0 || fraction.Denominator == 0) return false;
return this.AsDecimal() == fraction.AsDecimal();
}
private bool IsTrivial(Fraction fraction)
{
return(fraction.Numerator % 10 == 0 || fraction.Denominator % 10 == 0);
}
