public static List <List <T> > Permute <T>(this List <T> toBePermuted)
{
var permutation = new List <List <T> >();
int index = 0;
var totalOrder = new Dictionary <int, T>();
foreach (T item in toBePermuted)
{
totalOrder[index++] = item;
}
if (toBePermuted.Count() >= 13)
{
Console.WriteLine("List to big to Permute");
return(null);
}
var max = new Factoradic(FactorialTable.Get(toBePermuted.Count()));
var lehmerCode = new Factoradic(0);
int count = 0;
while (lehmerCode < max)
{
permutation.Add(DecodeLehmer(lehmerCode, totalOrder));
count++;
lehmerCode++;
}
return(permutation);
}
public static Factoradic operator ++(Factoradic a)
{
int aTen = a.ToBaseTen();
var sumFactoradic = new Factoradic(aTen + 1);
return(sumFactoradic);
}
public static Factoradic operator -(Factoradic a, Factoradic b)
{
int aTen = a.ToBaseTen();
int bTen = b.ToBaseTen();
int difference = aTen - bTen;
var diffFactoradic = new Factoradic(difference);
return(diffFactoradic);
}
public static Factoradic operator *(Factoradic a, Factoradic b)
{
int aTen = a.ToBaseTen();
int bTen = b.ToBaseTen();
int product = aTen * bTen;
var productFactoradic = new Factoradic(product);
return(productFactoradic);
}
public static Factoradic operator +(Factoradic a, Factoradic b)
{
int aTen = a.ToBaseTen();
int bTen = b.ToBaseTen();
int sum = aTen + bTen;
var sumFactoradic = new Factoradic(sum);
return(sumFactoradic);
}
public static Factoradic operator /(Factoradic a, Factoradic b)
{
int aTen = a.ToBaseTen();
int bTen = b.ToBaseTen();
int quotient = aTen / bTen;
var quotFactoradic = new Factoradic(quotient);
return(quotFactoradic);
}
public override bool Equals(Object a)
{
Factoradic b = a as Factoradic;
if (b == null)
{
return(false);
}
int bTen = b.ToBaseTen();
bool tF = bTen == baseTen;
return(tF);
}
private static List <T> DecodeLehmer <T>(Factoradic lehmerCode, Dictionary <int, T> totalOrder)
{
var decoded = new List <T>();
int max = totalOrder.Count;
var dictCopy = new List <T>(totalOrder.Select(x => x.Value));
for (int i = max - 1; i >= 0; i--)
{
int toBeAdded = lehmerCode.GetPlaceValue(i);
T item = dictCopy[toBeAdded];
decoded.Add(item);
dictCopy.Remove(item);
}
return(decoded);
}
