Talk:Square form factorization: Difference between revisions

Clearing some points
mNo edit summary
(Clearing some points)
Line 1:
Since most SquFoF solutions follow the examplefancy C code on Wp,
I will expose how it might fail to factor a composite number.
and why it is better to stick to the original algorithm.
 
Below 50,000,000 these N do not split:
Line 41 ⟶ 42:
49531597}</nowiki>
 
The regularitypattern suggests that 1 in every 1,351,351 N
won't factor, so more than 2^41 misses below 2^62.
 
Line 49 ⟶ 50:
 
Now look under the hood; m is the multiplier,
forms P# are onin the principal and A# onin an ambiguous cycle.<br/>
Each time, after just a few steps, the multiplier or some
trivial factor is returnedfound and the principal cycle exited:
 
<nowiki>N = 4558849
Line 80 ⟶ 81:
A9 = ( 22, 14146,-5455)</nowiki>
 
TheAnd patternso continueson. Not showing m = 15 through 385,
the last multiplier gives:
 
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where the problem doesn't exist.
 
This brings us to Shanks's approach.
This is what happens if the last square form is saved and we
The last square form is saved and if a trivial factor is found we
[[Square_Form_Factorization#Classical_heuristic|''continue searching the principal cycle'']]:
 
<nowiki>N = 4558849
Line 131 ⟶ 133:
A7 = ( 3, 7392,-5377)</nowiki>
 
and back onin the principal cycle where a proper square is
is but two steps away:
 
<nowiki>P14 = (-1898, 7334, 11^2)