 | CombinatoricFactorial Method |
Returns the factorial of the supplied value.
Namespace: Kaos.Combinatorics
Assembly: KaosCombinatorics (in KaosCombinatorics.dll) Version: 6.0.0.0
SyntaxC#
public static long Factorial( int value )
Parameters
- value
- Type: SystemInt32
Non-negative integer.
Return Value
Type: Int64For increasing value starting at 0, returns 1, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880, 3628800, 39916800, 479001600, 6227020800, 87178291200, 1307674368000, 20922789888000, 355687428096000, 6402373705728000, 121645100408832000, 2432902008176640000.
Exceptions| Exception | Condition |
|---|---|
| IndexOutOfRangeException | When value not in range (0..20). |
Examples
The number of rows in a Permutation table of n choices is:
Combinatoric.Factorial (n)
The number of rows in a Permutation table of k picks
from n choices is:
Combinatoric.Factorial (n) / Combinatoric.Factorial (n-k)
An exception to the above formulas is the special case where the number of elements in the permutation is 0. While mathematics treats this result as 1 row containing the empty product, this library returns 0 rows.
See Also