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+--- Thread: primitive root (/thread-4612.html)
primitive root - roadrunner - 09-01-2015 01:28 PM
function next_primitive_root(n,p) returns the smallest primitive root of "p" that is larger than "n"
example:
next_primitive_root(5, 13) returns 6
next_primitive_root(Ans,13) returns 7
<enter> returns 11
<enter> returns "no primitive roots exist"
Code:
#pragma mode( separator(.,;) integer(h32))
EXPORT next_primitive_root(n,p)
BEGIN
local a,b,c,j,k;
a:=euler(p);
b:=ifactors(a);
c:=length(b);
for j from n+1 to p−1 do
for k from 1 to c step 2 do
if powmod(j,a/b(k),p) == 1 then
break;
end;
if (k == c-1) and (gcd(j,p)==1) then
return j;
end;
end;
end;
return "no primitive roots exist";
END;