From 59d2cce8a1493c0c68cda6fcf09729e0151ac99d Mon Sep 17 00:00:00 2001 From: Reiner Herrmann Date: Wed, 22 Sep 2010 15:39:09 +0200 Subject: projecteuler solution 060 --- src/projecteuler/060.py | 49 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) create mode 100644 src/projecteuler/060.py (limited to 'src') diff --git a/src/projecteuler/060.py b/src/projecteuler/060.py new file mode 100644 index 0000000..22d1311 --- /dev/null +++ b/src/projecteuler/060.py @@ -0,0 +1,49 @@ +from common import sieve + +# +# WARNING: uses a lot of RAM! +# +# notes: +# - limit:1000000, sieve:50000000 -> no result when starting with ["3"] or ["7"] +# - limit:800000, sieve:50000000 -> no result! +# - limit:100000, sieve:100000000 -> [['13', '5197', '5701', '6733', '8389']] +# +# + +limit = 9000 + +primes = sieve(int(str(limit)+str(limit))).primes() +prime_list = [ p for p in primes if p < limit] +prime_list.sort() +prime_list_str = [ str(p) for p in prime_list ] + +def check_list(l): + result = [] + for sublist in l: + for p in prime_list_str: + isprime = True + for n in sublist: + if int(n+p) not in primes or int(p+n) not in primes: + isprime = False + break + if isprime: + result += [ sublist+[p] ] + + return result + + +def cleanup(l): + result = [] + for sublist in l: + sublist.sort() + if sublist not in result: + result += [sublist] + return result + + +l = [ [p] for p in prime_list_str ] +for i in range(4): + l = cleanup(check_list(l)) + +print l + -- cgit v1.2.3