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Solves problem 13
Prepares problem 14 (hummm, though one it seems)
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16
e_13.py
16
e_13.py
@@ -11,9 +11,21 @@
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"""
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def ten_dig_sum(filename):
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"""
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Returns the first 10 digits of the sum of all numbers in filename.
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"""
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return int(str(sum(load_data(filename)))[0:10])
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return 1
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def load_data(filename):
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"""
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Loads the data from a file into a table
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"""
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file = open(filename, "r")
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data = []
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for line in file :
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data.append(int(line))
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file.close()
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return data
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if __name__ == '__main__':
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print "Answer : %d" % (fun())
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#data = ten_dig_sum("e_13.data")
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print "Answer : %d" % (ten_dig_sum("e_13.data"))
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34
e_14.py
Executable file
34
e_14.py
Executable file
@@ -0,0 +1,34 @@
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#!/usr/bin/env python
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"""
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##---
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# jlengrand
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#Created on : Mon Jan 16 10:22:33 CET 2012
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#
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# DESCRIPTION : Solves problem 14 of Project Euler
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The following iterative sequence is defined for the set of positive integers:
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n -> n/2 (n is even)
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n -> 3n + 1 (n is odd)
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Using the rule above and starting with 13, we generate the following sequence:
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13 -> 40 -> 20 -> 10 -> 5 -> 16 -> 8 -> 4 -> 2 -> 1
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It can be seen that this sequence (starting at 13 and finishing at 1) contains
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10 terms.
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Although it has not been proved yet (Collatz Problem), it is thought that all
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starting numbers finish at 1.
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Which starting number, under one million, produces the longest chain?
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NOTE: Once the chain starts the terms are allowed to go above one million.
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##---
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"""
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def longest_chain(max_value):
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"""
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Returns the starting number under max_value that produces the longest
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chain given the sequence.
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"""
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return 1
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if __name__ == '__main__':
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print "Answer : %d" % (longest_chain(1000000))
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