>>>>> On Thu, 17 Jun 2021, Guilherme Amadio wrote: > There's actually a much simpler solution to this:
> $ is_prime() { test $(factor $1 | cut -d: -f2 | wc -w) == 1; }
> $ for n in $(seq 0 10); do is_prime $n && echo $n is prime; done
> 2 is prime
> 3 is prime
> 5 is prime
> 7 is prime
> $ time factor 20187319083467888113
> 20187319083467888113: 20187319083467888113
> 0.00
This depends on the actual domain of numbers. If the primes involved
have 20 digits as in your example, then factor should be used of course.
I suspect though that we're talking about small numbers (below 100?)
here, in which case a solution in pure bash would be preferable.
Ulrich
signature.asc
Description: PGP signature
