public void GetAmicableNumber_Throws_Exception_When_Input_Number_Is_Not_Part_Of_Amicable_Pair()
{
var inputNumber = 13;
Action getAmicableNumber = () => GeneralHelpers.GetAmicableNumber(13);
getAmicableNumber.Should().Throw <NotPartOfAmicablePairException>()
.WithMessage($"{inputNumber} is not part of an amicable pair.");
}
/// <summary>
/// Run solution for problem 21.
/// </summary>
/// <param name="rangeThreshold">Range threshold.</param>
/// <returns>Sum of amicable numbers below <paramref name="rangeThreshold"/>.</returns>
public static int Run(int rangeThreshold)
{
var amicableNumbersSum = 0;
for (var i = 3; i < rangeThreshold; i += 1)
{
try
{
var amicableNumber = GeneralHelpers.GetAmicableNumber(i);
if (amicableNumber != 0)
{
amicableNumbersSum += i + amicableNumber;
i = amicableNumber;
}
}
catch (NotPartOfAmicablePairException)
{
}
}
return(amicableNumbersSum);
}
public void GetAmicableNumber_Returns_Input_Numbers_Amicable_Number()
{
GeneralHelpers.GetAmicableNumber(220).Should().Be(284);
}