Rosetta Code

Lucas-Lehmer test: Difference between revisions

Page Discussion

Lucas-Lehmer test (view source)

Revision as of 07:22, 22 July 2010

449 bytes added ,  13 years ago
m
→‎[[Lucas-Lehmer_test#ALGOL 68]]: fix pre tag
(Completed output)
Line 67:
 
=={{header|ALGOL 68}}==
{{works with|algol68gALGOL 68|Revision 1 -mk11 no extensions to language used}}
<lang algol68>main:(▼
PRAGMAT stack=1M precision=20000 PRAGMAT▼
 
{{works with|ALGOL 68G|Any - tested with release [http://sourceforge.net/projects/algol68/files/algol68g/algol68g-1.18.0/algol68g-1.18.0-9h.tiny.el5.centos.fc11.i386.rpm/download 1.18.0-9h.tiny]}}
PROC is prime = ( INT p )BOOL:▼
{{wont work with|ELLA ALGOL 68|Any (with appropriate job cards) - tested with release [http://sourceforge.net/projects/algol68/files/algol68toc/algol68toc-1.8.8d/algol68toc-1.8-8d.fc9.i386.rpm/download 1.8-8d] - due to extensive use of FORMATted transput}}
IF p = 2 THEN TRUE▼
▲<lang algol68>main:(
ELIF p <= 1 OR p MOD 2 = 0 THEN FALSE▼
▲ PRAGMAT stack=1M precision=20000 PRAGMAT
ELSE▼
BOOL prime := TRUE;
FOR i FROM 3 BY 2 TO ENTIER sqrt(p)
WHILE prime := p MOD i /= 0 DO SKIP OD;▼
prime▼
FI;▼
 
PROC is mersenne prime = ( INT p )BOOL:
IF p = 2 THEN TRUE
▲ ELIF p <= 1 OR p MOD 2 = 0 THEN FALSE
ELSE▼
▲ ELSE
LONG LONG INT m p := LONG LONG 2 ** p - 1, s := 4;▼
BOOL prime FROM:= 3 TO p DOTRUE;
FOR i FROM 3 s := (s **BY 2 -TO 2) MOD mENTIER sqrt(p)
▲ WHILE prime := p MOD i /= 0 DO SKIP OD;
OD;
s = 0prime
FI;
 
▲ PROC is mersenne prime = ( INT p )BOOL:
▲ IF p = 2 THEN TRUE
▲ ELSE
▲ LONG LONG INT m p := LONG LONG 2 ** p - 1, s := 4;
FROM 3 TO p DO
s := (s ** 2 - 2) MOD m p
▲ FIOD;
▲ s = prime0
FI;
 
test:(
INT upb prime = ( long long bits width - 1 ) OVER 2; # no unsigned #
INT upb count = 45; # find 45 mprimes if INT has enough bits #
Line 108 ⟶ 112:
)</lang>
Output:
<pre>
<lang algol68>Finding Mersenne primes in M[2..33252]:
M2 M3 M5 M7 M13 M17 M19 M31 M61 M89 M107 M127 M521 M607 M1279 M2203 M2281 M3217 M4253 M4423 M9689 M9941 M11213 M19937 M21701 M23209</lang>
</pre>
See also: http://www.xs4all.nl/~jmvdveer/mersenne.a68.html
 
Retrieved from "https://rosettacode.org/wiki/Special:MobileDiff/57893"