/// <summary>
/// Returns all k combinations of given set
/// </summary>
public static List <List <T> > NCombinations(List <T> set, uint k)
{
int cap = (int)Recursive.Factorial((uint)set.Count) / (int)Recursive.Factorial(k) * (int)Recursive.Factorial((uint)set.Count - k);
var results = new List <List <T> >(cap);
NCombinationsInner(0, new int[k], set, results);
return(results);
}
/// <summary>
/// Computes factorial of n (complexity O(n))
/// </summary>
public static ulong Factorial(uint n)
{
if (n == 0)
{
return(1);
}
return(Recursive.Factorial(n - 1) * n);
}
