Function permutator::divide_factorial

pub fn divide_factorial<T>(numerator: T, denominator: T) -> T where
    T: PrimInt + Unsigned + Product, 

Calculate factorial for two factorial division. It’ll return 1 if numerator is smaller or equals to denominator. Otherwise, it’ll short circuit the calculation by calculate only the undivided remainder.

Examples

use permutator::divide_factorial;
 
// calculate 5!/3!
divide_factorial(5u8, 3u8); // return 5 * 4 = 20
// calculate 3!/5!
divide_factorial(3u32, 5u32); // return 1.
// calculate 5!/5!
divide_factorial(5u16, 5u16); // return 1.