> ...
> Michael
>
you have won!
>
> --- /usr/src/games/factor/factor.c Wed Oct 28 00:59:24 2009
> +++ factor.cTue Sep 8 20:06:44 2015
> @@ -192,6 +192,19 @@ pr_fact(u_int64_t val) /* Factor this value.
> */
> (void)putchar('\n');
> }
>
> +static u_int32_t
> +i
On 09/08/15 08:03, Otto Moerbeek wrote:
> My bet would be Newton iteration, which should converge faster than
> binary search. ping(8) has an implementation of integer sqrt.
>
> BTW, long double won't fix the problem on al platforms since it is not
> guaranteed to be longer than double.
Newton is
On 2015-09-07, Otto Moerbeek wrote:
> The game is to fix the bugs
FWIW, FreeBSD has changed factor(6) to use libcrypto's BN functions.
--
Christian "naddy" Weisgerber na...@mips.inka.de
Hereâs a function that computes unsigned long square roots using Newtonâs
method.
I believe that I have tested it quite carefully and am quite confident that it
works correctly.
It returns the unsigned long exact square root value if there is one.
Otherwise, it returns the closest unsigned lo
On Mon, Sep 07, 2015 at 06:20:02PM -0400, Raul Miller wrote:
> On Mon, Sep 7, 2015 at 6:03 PM, Ted Unangst wrote:
> > Michael Warmuth-Uhl wrote:
> >> On 2015-09-07, Otto Moerbeek wrote:
> >> It seems to fix the issues on amd64, but I'm not sure if the accuracy of
> >> long double and sqrtl is gua
there's more..
* worst case is 18446744030759878681, which is
previous_prime(sqrt(2^64))^2, which is
4294967291^2
* _smallest_ OpenBSD composite prime seems to be 4295360521,
which is 65539^2
Michal Bozon
On Mon, Sep 7, 2015 at 6:03 PM, Ted Unangst wrote:
> Michael Warmuth-Uhl wrote:
>> On 2015-09-07, Otto Moerbeek wrote:
>> It seems to fix the issues on amd64, but I'm not sure if the accuracy of
>> long double and sqrtl is guaranteed to be enough in general.
>
> using floating point seems suspect.
Michael Warmuth-Uhl wrote:
> Hello,
>
> On 2015-09-07, Otto Moerbeek wrote:
> > The game is to fix the bugs
>
> Below is my attempt to play this game.
>
> It seems to fix the issues on amd64, but I'm not sure if the accuracy of
> long double and sqrtl is guaranteed to be enough in general.
usin
Hello,
On 2015-09-07, Otto Moerbeek wrote:
> The game is to fix the bugs
Below is my attempt to play this game.
It seems to fix the issues on amd64, but I'm not sure if the accuracy of
long double and sqrtl is guaranteed to be enough in general.
Regards,
Michael
--- /usr/src/games/factor/fact
On Mon, Sep 07, 2015 at 06:23:49PM +0200, Michal Bozon wrote:
> .. i was wondering before, why *bin/factor is in games, now i get it.
> Very nice observation!
>
> Another factor game fake primes:
>
> 18446744073709551503 == 2^64 - 113 == 119026343 * 154980348121
> 18446744073709551499 == 2^64 -
.. i was wondering before, why *bin/factor is in games, now i get it.
Very nice observation!
Another factor game fake primes:
18446744073709551503 == 2^64 - 113 == 119026343 * 154980348121
18446744073709551499 == 2^64 - 117 == 363269 * 50779846542671
18446744073709551491 == 2^64 - 125 == 31578160
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