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Work on primes to be performed. dump has been created to avoid recalculation each time. But I 'll spend some time working on sieves. Signed-off-by: Julien Lengrand-Lambert <julien@lengrand.fr>
51 lines
1.2 KiB
Python
51 lines
1.2 KiB
Python
#!/usr/bin/env python
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"""
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##---
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# Julien Lengrand-Lambert
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#Created on : Thu Jan 19 10:12:06 CET 2012
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#
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# DESCRIPTION : Puts the list of all primes below one million in a file.
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Seeing the number of problems using primes, this could be useful
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##---
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"""
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import pickle
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def is_prime(value):
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"""
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Returns True or False depending whether value is prime or not.
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"""
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start = 2
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while (start <= value / 2):
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if value % start == 0 :
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return False
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else :
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start += 1
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return True
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def prime_list(max_val):
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"""
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Returns a list of all primes below max_val
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"""
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plist = []
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cur = 2
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while (cur < max_val):
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if (cur % 1000) == 0:
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print "%d/%d" % (cur, max_val)
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if (is_prime(cur)):
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plist.append(cur)
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cur += 1
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return plist
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if __name__ == '__main__' :
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if 0: # creating file
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plist = prime_list(1000000)
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# dumping into primes_list.dump
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pickle.dump(plist, open("primes_list.dup", "wb"))
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else: # reading and using file
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plist = pickle.load(open("primes_list.dup", "rb"))
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print plist[0:100]
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raw_input()
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print "Done!"
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