Ascending primes: Difference between revisions

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===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.

<syntaxhighlight lang="~~ecmascript~~">import "./math" for Int

<syntaxhighlight lang="wren">import "./math" for Int

import "./seq" for Lst

import "./fmt" for Fmt

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ascPrimes.addAll(higherPrimes)

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

~~for (chunk in Lst.chunks(ascPrimes, 10))~~ Fmt.~~print~~("$8d", ~~chunk~~)</syntaxhighlight>

Fmt.tprint("$8d", ascPrimes, 10)</syntaxhighlight>

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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.

<syntaxhighlight lang="~~ecmascript~~">import "./set" for Set

<syntaxhighlight lang="wren">import "./set" for Set

import "./math" for Int

import "./seq" for Lst

import "./fmt" for Fmt

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ascPrimes.sort()

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

~~for (chunk in Lst.chunks(ascPrimes, 10))~~ Fmt.~~print~~("$8s", ~~chunk~~)</syntaxhighlight>

Fmt.tprint("$8d", ascPrimes, 10)</syntaxhighlight>