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31 lines
965 B
Python
31 lines
965 B
Python
#!/usr/bin/env python
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'''
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Created on 10 feb. 2012
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@author: Julien Lengrand-Lambert
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DESCRIPTION: Solves problem 58 of Project Euler
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Starting with 1 and spiralling anticlockwise in the following way,
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a square spiral with side length 7 is formed.
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37 36 35 34 33 32 31
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38 17 16 15 14 13 30
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39 18 5 4 3 12 29
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40 19 6 1 2 11 28
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41 20 7 8 9 10 27
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42 21 22 23 24 25 26
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43 44 45 46 47 48 49
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It is interesting to note that the odd squares lie along the bottom right diagonal,
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but what is more interesting is that 8 out of the 13 numbers lying along both
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diagonals are prime; that is, a ratio of 8/13 ≈ 62%.
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If one complete new layer is wrapped around the spiral above, a square spiral
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with side length 9 will be formed. If this process is continued,
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what is the side length of the square spiral for which the ratio of primes
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along both diagonals first falls below 10%?
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'''
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if __name__ == '__main__':
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print "plouf"
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#print "Answer : %d " % (last_ten()) |