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Forum: Factoring 2022-06-12, 22:58
Replies: 20
Views: 973
Posted By R. Gerbicz
Interesting, still yesterday thought that every...

Interesting, still yesterday thought that every number goes to cycle.

Looks like 578 is the first number that goes to infinity!
After 2000 iterations the factorization begins with: [2, 123877; 3,...
Forum: And now for something completely different 2022-06-01, 20:48
Replies: 169
Views: 10,447
Posted By R. Gerbicz
You could not make a certificate, that would...

You could not make a certificate, that would violate the ecpp method's proof.
To hack the initial prp test is not that hard: use my super prp prime, see...
Forum: And now for something completely different 2022-05-31, 13:51
Replies: 169
Views: 10,447
Posted By R. Gerbicz
There is no Jacobi check on general numbers, we...

There is no Jacobi check on general numbers, we have error check but that is somewhat slow on these general numbers and you really don't need any check on these tiny numbers.



Any fancy Lucas...
Forum: And now for something completely different 2022-05-29, 12:01
Replies: 169
Views: 10,447
Posted By R. Gerbicz
Great, don't know what is the memory usage in the...

Great, don't know what is the memory usage in the 2nd phase, if that would be too large then you can complete that phase on another computer with more memory. That phase is much faster than the 1st...
Forum: And now for something completely different 2022-05-28, 21:24
Replies: 169
Views: 10,447
Posted By R. Gerbicz
For those who has big guns. I believe this...

For those who has big guns.
I believe this could be faster, for that runs where the current code spends a lot of time on trial division comparing to the the total running time [big N value with a...
Forum: And now for something completely different 2022-05-20, 15:34
Replies: 169
Views: 10,447
Posted By R. Gerbicz
Btw what the current code is doing is already an...

Btw what the current code is doing is already an overshoot, though not that much, in nt.c:

int cm_nt_is_prime (mpz_t a)

{
return (mpz_probab_prime_p (a, 0) > 0);
}

Because with that you...
Forum: And now for something completely different 2022-05-19, 00:46
Replies: 169
Views: 10,447
Posted By R. Gerbicz
With a newer gcc-10.3.0 using that it is worked,...

With a newer gcc-10.3.0 using that it is worked, thank you all! Of course quickly proved that 1k, with a 4k:

gerbicz@gerbicz-MS-7972:~/cmexp3/cm-0.4.1dev/src$ mpirun ecpp-mpi -v -g -n...
Forum: And now for something completely different 2022-05-18, 22:38
Replies: 169
Views: 10,447
Posted By R. Gerbicz
I have Ubuntu 18.10. And this one? ...

I have Ubuntu 18.10.

And this one?

root@gerbicz-MS-7972:/home/gerbicz/cmexp3/cm-0.4.1dev/src# mpirun --version
HYDRA build details:
Version: 3.3a2
...
Forum: And now for something completely different 2022-05-18, 20:27
Replies: 169
Views: 10,447
Posted By R. Gerbicz
On my oldish core i7 6700, I can only get this...

On my oldish core i7 6700, I can only get this quickly:

gerbicz@gerbicz-MS-7972:~/cmexp3/cm-0.4.1dev/src$ mpirun -np 4 ecpp-mpi -g -n '10^1000+453' -c -f cert-1000
MPI with 3 workers initialised,...
Forum: And now for something completely different 2022-05-18, 16:27
Replies: 169
Views: 10,447
Posted By R. Gerbicz
It gives: ...

It gives:
root@gerbicz-MS-7972:/home/gerbicz/cmexp3/cm-0.4.1dev# mpirun --bind-to core ecpp-mpi
MPI with 0 workers initialised, of which 0 are local....
Forum: And now for something completely different 2022-05-18, 13:13
Replies: 169
Views: 10,447
Posted By R. Gerbicz
Some progress, but now "MPI with 0 workers...

Some progress, but now
"MPI with 0 workers initialised, of which 0 are local."
which is quite few, but surprisingly all 8 threads are running, but no screen/file output (after 20 minutes killed...
Forum: And now for something completely different 2022-05-17, 21:28
Replies: 169
Views: 10,447
Posted By R. Gerbicz
Used ./configure then make install I have only...

Used ./configure then make install
I have only ecpp in src library, what I can nicely run, using one thread.
Why the ecpp.mpi is not compiled??
Forum: And now for something completely different 2022-05-15, 17:13
Replies: 169
Views: 10,447
Posted By R. Gerbicz
Yeah. One very "trivial" improvement would come...

Yeah. One very "trivial" improvement would come to call a faster prp routine, so not call the gmp's built-in mpz_probab_prime_p function. Maybe use pfgw, or directly using the gw library. Notice that...
Forum: Factoring 2022-04-20, 23:46
Replies: 30
Views: 1,814
Posted By R. Gerbicz
False, another way is to show a 1<d<n divisor,...

False, another way is to show a 1<d<n divisor, say an algebraic divisor, and then (easily) prove that d or n/d is composite, then n is not semiprime. What is also a possible case in this sequence of...
Forum: Puzzles 2022-04-17, 20:33
Replies: 3
Views: 891
Posted By R. Gerbicz
All non-negative integers are reachable! ...

All non-negative integers are reachable!
consider the following 9 ways of reductions, the first number is always the starter, then we show each following numbers in the routine:
8*N+1 -> 24*N+3 ->...
Forum: Dobri 2022-04-11, 15:47
Replies: 16
Views: 1,479
Posted By R. Gerbicz
On quantum computer we already have the...

On quantum computer we already have the polynomial time factorization Shor's algorithm.
I'd say it is quite unlikely that the quad binary approach would be in polynomial time using quantum [because...
Forum: Dobri 2022-04-11, 15:09
Replies: 16
Views: 1,479
Posted By R. Gerbicz
And of course this is not a simplification of the...

And of course this is not a simplification of the problem, because it is a quadratic optimization problem using binary integers.
And I'd prefer this (known) form:

min{0 : x*y=n, x>=2, y>=2, x and...
Forum: Miscellaneous Math 2022-04-10, 22:37
Replies: 14
Views: 1,275
Posted By R. Gerbicz
Recommending 6 (six) more problems what you could...

Recommending 6 (six) more problems what you could easily attack: https://en.wikipedia.org/wiki/Millennium_Prize_Problems
all of them worth 1 million bucks (USD).
Forum: GMP-ECM 2022-04-01, 16:17
Replies: 24
Views: 2,172
Posted By R. Gerbicz
I've needed also: sudo apt-get install...

I've needed also:

sudo apt-get install libtool
Forum: Lounge 2022-03-15, 18:58
Replies: 169
Views: 33,133
Posted By R. Gerbicz
Recent video about William Shanks, who hold the...

Recent video about William Shanks, who hold the record computation of pi for almost a century: https://www.youtube.com/watch?v=DmfxIhmGPP4
And a follow up video to find the first 100 digits of pi by...
Forum: Puzzles 2022-02-23, 15:17
Replies: 13
Views: 1,854
Posted By R. Gerbicz
Yes, you're right.

Yes, you're right.
Forum: Puzzles 2022-02-22, 16:09
Replies: 13
Views: 1,854
Posted By R. Gerbicz
That is a very nice puzzle, complete solution...

That is a very nice puzzle, complete solution (with little maths):

Work mod 5, since there are 5 different things that Penn and Teller can choose, say they have chosen x on the left and y on the...
Forum: Puzzles 2022-02-21, 12:41
Replies: 14
Views: 1,295
Posted By R. Gerbicz
Hm, it is even faster: static inline bool...

Hm, it is even faster:

static inline bool issquare(uint64_t x)
{
uint64_t sqr = 0.5+sqrt(x);
return sqr * sqr == x;
}

and gives correct answer for the full [0,2^64) range (for the same...
Forum: Puzzles 2022-02-20, 21:13
Replies: 14
Views: 1,295
Posted By R. Gerbicz
It is easier: uint64_t sqr = sqrtl(x); return...

It is easier:
uint64_t sqr = sqrtl(x);
return sqr * sqr == x;

if you call it for 64 bits number, so 0<=x<2^64, then 0<=sqr<2^32, so it couldn't report a nonsquare number as a square, because in...
Forum: Puzzles 2022-02-20, 20:57
Replies: 14
Views: 1,295
Posted By R. Gerbicz
Using one core that is true, and it is almost...

Using one core that is true, and it is almost true for many cores/threads, because we're testing res values in increasing order, just check a%M values.



Good question, but it seems that the...
Showing results 1 to 25 of 1000

 
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