Ascending primes: Difference between revisions

===Version 1 (Sieve)===

Although they use a lot of memory, sieves usually produce good results in Wren and here we only need to sieve for primes up to 3456789 as there are just 9 possible candidates with 8 digits and 1 possible candidate with 9 digits which we can test for primality individually. The following runs in around 0.43 seconds.

import "./fmt" for Fmt

 

ascPrimes.addAll(higherPrimes)

System.print("There are %(ascPrimes.count) ascending primes, namely:")

 

{{out}}

 

Much quicker than the 'sieve' approach at 0.013 seconds. I also tried using a powerset but that was slightly slower at 0.015 seconds.

import "./math" for Int

import "./fmt" for Fmt

 

ascPrimes.sort()

System.print("There are %(ascPrimes.count) ascending primes, namely:")

 

{{out}}