/// <summary>
/// https://projecteuler.net/problem=53
/// </summary>
/// <param name="arguments"></param>
/// <returns></returns>
public static Result CombinatoricSelections(Problem arguments)
{
var limit = arguments.IntNumber;
var count = 0;
//todo: use factaorial in loop and cache it in array
for (int n = 1; n <= 100; n++)
{
for (int r = 1; r < n; r++)
{
if (UtilityMath.BinomialCoefficients(n, r) >= limit)
{
count++;
}
}
}
var answer = count.ToString();
var message = string.Format("{0} not necessarily distinct, values of nCr, for 1 ≤ n ≤ 100, are greater than {1}.", answer, limit);
if (Answers[arguments.Id] != answer)
{
message += string.Format(" => INCORRECT ({0})", Answers[arguments.Id]);
}
var result = new Result(arguments.Id, message)
{
Answer = answer
};
return(result);
}
