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Lucas-Lehmer test: Difference between revisions

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Lucas-Lehmer test (view source)

Revision as of 21:24, 5 November 2008

64 bytes removed ,  15 years ago
→‎{{header|Python}}: python colorization, remove nonpythonic syntax
(→‎{{header|Python}}: python colorization, remove nonpythonic syntax)
Line 391:
 
=={{header|Python}}==
<python> from sys import stdout
from math import sqrt, log
fi = od = None
def is_prime ( p ):
Line 399 ⟶ 398:
elif p <= 1 or p % 2 == 0: return False
else:
for i in range(3, int(sqrt(p))+1, 2 ): # do▼
prime = True;▼
▲ for i in range(3, int(sqrt(p))+1, 2 ): # do
if p % i == 0: return False
else:return True
return True
fi
fi;
def is_mersenne_prime ( p ):
if p == 2: return True
▲ prime =return True;
else:
m_p = ( 1 << p ) - 1; s = 4;
fors i= in range(3, p+1): # do4;
for i in range(3, p+1):
s = (s ** 2 - 2) % m_p
od;
return s == 0
fi;
precision = 20000; # maximum requested number of decimal places of 2 ** MP-1 #
long_bits_width = precision / log(2) * log(10);
upb_prime = int( long_bits_width - 1 ) / 2; # no unsigned #
upb_count = 45; # find 45 mprimes if int was given enough bits #
print ((" Finding Mersenne primes in M[2..%d]:"%upb_prime));
count=0;
for p in range(2, upb_prime+1): # do
if is_prime(p) and is_mersenne_prime(p):
print("M%d"%p),
stdout.flush();
count += 1
fi;
if count >= upb_count: break
print</python>
od
print
 
Output:
<pre> Finding Mersenne primes in M[2..33218]:
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</pre>
 
=={{header|Scheme}}==
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