public static Int64 Factorial(this Int64 source)
{
if (source == 0)
{
return(1);
}
return(FiniteIntList.GetItems(1, source).Aggregate((result, item) => result *= item));
}
public static Object Solve()
{
return(FiniteIntList.GetItems(Money, 0, 200).SelectMany(
a => FiniteIntList.GetItems(a, 0, 100).SelectMany(
b => FiniteIntList.GetItems(b, 0, 50).SelectMany(
c => FiniteIntList.GetItems(c, 0, 20).SelectMany(
d => FiniteIntList.GetItems(d, 0, 10).SelectMany(
e => FiniteIntList.GetItems(e, 0, 5).SelectMany(
f => FiniteIntList.GetItems(f, 0, 2).Select(
counter => 1))))))).Count());
}
public static Object Solve()
{
return(FiniteIntList.GetItems(2, 9).SelectMany(d => FiniteIntList.GetItems(d - 1, 1).Select(n => new Fraction(n, d))) // Generates a list of all possible lowest term fractions (4/8)
.Select(f => new // Expands all lowest term fractions to include all possible higher term fractions (49/98)
{
f,
fl = FiniteIntList.GetItems(1, 9).Select(p => new Fraction(f.n + p * 10, f.d + p * 10)).Concat(
FiniteIntList.GetItems(1, 9).Select(p => new Fraction(f.n + p * 10, f.d * 10 + p))).Concat(
FiniteIntList.GetItems(1, 9).Select(p => new Fraction(f.n * 10 + p, f.d + p * 10))).Concat(
FiniteIntList.GetItems(1, 9).Select(p => new Fraction(f.n * 10 + p, f.d * 10 + p)))
.Where(l => l.n < l.d)
})
.SelectMany(o => o.fl.Where(fl => fl == o.f)) // Select all higher term fractions that equal their lower term fraction
.Multiply()
.Normalize()
.Denominator);
}
