Re: Prime list

Hello,
when i was writing Tk Tartaglia's triangle fun - Pascal's triangle fun i needed to check for primality and i found this thread with this fast solution; maybe you learn something from it

HtH
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Re^2: Prime list by danaj (Friar) on Feb 12, 2015 at 17:19 UTC
I would suggest actually looking at a sieve, for example the ones on RosettaCode. They are much faster than the trial division method you link to, albeit generating primes starting at two. For doing trial division, the skip-2-3 primality test from RosettaCode is twice as fast as the code you link to. Just wrap in something like: `my @primes = grep { isprime($_) } 1..1000000;` While the regex solution mentioned in another reply is super clever, it is also super not useful for the task once past toy sizes.	[reply] [d/l]

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Re^2: Prime list
by danaj (Friar) on Feb 12, 2015 at 17:19 UTC

I would suggest actually looking at a sieve, for example the ones on RosettaCode. They are much faster than the trial division method you link to, albeit generating primes starting at two.

For doing trial division, the skip-2-3 primality test from RosettaCode is twice as fast as the code you link to. Just wrap in something like: my @primes = grep { isprime($_) } 1..1000000;

While the regex solution mentioned in another reply is super clever, it is also super not useful for the task once past toy sizes.

[reply]
[d/l]