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50 lines
1.7 KiB
Python
50 lines
1.7 KiB
Python
#!/usr/bin/env python
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'''
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Created on 2 may 2012
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@author: Julien Lengrand-Lambert
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DESCRIPTION: Solves problem 38 of Project Euler
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Take the number 192 and multiply it by each of 1, 2, and 3:
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192 * 1 = 192
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192 * 2 = 384
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192 * 3 = 576
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By concatenating each product we get the 1 to 9 pandigital, 192384576. We will call 192384576 the concatenated product of 192 and (1,2,3)
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The same can be achieved by starting with 9 and multiplying by 1, 2, 3, 4, and 5, giving the pandigital, 918273645, which is the concatenated product of 9 and (1,2,3,4,5).
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What is the largest 1 to 9 pandigital 9-digit number that can be formed as the concatenated product of an integer with (1,2, ... , n) where n >1?
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'''
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def has_duplicates(mylist):
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"""
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Returns True if the list contains at least one duplicate
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"""
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return (len(mylist)!=len(set(mylist)))
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def concat_pandigital():
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"""
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Returns the largest 1 to 9 pandigital number formed as the concatened product of an integer with (1, 2, ..., n)
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"""
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pand_list = []
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# max_val is number for which sum(len(max_val * 1) + len(max_val * 2) ) > 9 = 10000
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for x in range(1, 10000):
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got = "" # list of all numbers we already have
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mul = 1
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doit = 1
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while doit:
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cur_val = x * mul
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if (("0" in str(cur_val)) or (has_duplicates(got + str(cur_val)))):
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doit = 0
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else:
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got += str(cur_val)
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mul += 1
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if len(got) == 9: # we have a pandigital number in output
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print x
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pand_list.append(int(got)) # should put got back in a correct way
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return max(pand_list)
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if __name__ == '__main__':
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print "Answer : %d " % (concat_pandigital()) |