Factorial

Computes !, the factorial, of integers.

Factorial(x) = x! = x * (x-1) * (x-2) * (...) * 2 * 1

Internals:

This implementation relies on scala.math.BigInt to avoid the notorious overflow problems of factorial functions; 13! overflows Int and 21! overflows Long.

for x! where 0 <= x <= 100, returns a cached value. for x! where x > 100, starts with 100! from the cache and iteratively multiplies 101, 102, ... x.

Computes x!, the factorial(x), of Long x.

Factorial(x) = x! = x * (x-1) * (x-2) * (...) * 2 * 1

Internals:

This implementation relies on scala.math.BigInt to avoid the notorious overflow problems of factorial functions; 13! overflows Int and 21! overflows Long.

for x! where 0 <= x <= 100, returns a cached value. for x! where x > 100, starts with 100! from the cache and iteratively multiplies 101, 102, ... x.

Computes x!, the factorial(x), of BigInt x.

Factorial(x) = x! = x * (x-1) * (x-2) * (...) * 2 * 1

Internals:

This implementation relies on scala.math.BigInt to avoid the notorious overflow problems of factorial functions; 13! overflows Int and 21! overflows Long.

for x! where 0 <= x <= 100, returns a cached value. for x! where x > 100, starts with 100! from the cache and iteratively multiplies 101, 102, ... x.