mirror of
https://github.com/lcn2/calc.git
synced 2025-08-16 01:03:29 +03:00
35 lines
612 B
Plaintext
35 lines
612 B
Plaintext
/*
|
|
* Copyright (c) 1995 David I. Bell
|
|
* Permission is granted to use, distribute, or modify this source,
|
|
* provided that this copyright notice remains intact.
|
|
*
|
|
* Factor using Pollard's p-1 method.
|
|
*/
|
|
|
|
define factor(N, B, ai, af)
|
|
{
|
|
local a, k, i, d;
|
|
|
|
if (isnull(B))
|
|
B = 1000;
|
|
if (isnull(ai))
|
|
ai = 2;
|
|
if (isnull(af))
|
|
af = ai + 20;
|
|
k = lcmfact(B);
|
|
d = lfactor(N, B);
|
|
if (d > 1)
|
|
return d;
|
|
for (a = ai; a <= af; a++) {
|
|
i = pmod(a, k, N);
|
|
d = gcd(i - 1, N);
|
|
if ((d > 1) && (d != N))
|
|
return d;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
if (config("lib_debug") >= 0) {
|
|
print "factor(N, B, ai, af) defined";
|
|
}
|