42 lines
859 B
Python
42 lines
859 B
Python
#!/usr/bin/env python3
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"""
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Created on 14 Mar 2017
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@author: David Doblas Jiménez
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@email: daviddoji@pm.me
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Solution for problem 2 of Project Euler
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https://projecteuler.net/problem=2
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"""
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from utils import timeit
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@timeit("Problem 2")
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def compute():
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"""
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Each new term in the Fibonacci sequence is generated by adding the
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previous two terms. By starting with 1 and 2, the first 10 terms will be:
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1, 2, 3, 5, 8, 13, 21, 34, 55, 89, ...
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Find the sum of all the even-valued terms in the sequence which do not
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exceed four million.
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"""
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ans = 0
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limit = 4_000_000
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x, y = 1, 1
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z = x + y # Because every third Fibonacci number is even
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while z <= limit:
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ans += z
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x = y + z
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y = z + x
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z = x + y
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return ans
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if __name__ == "__main__":
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print(f"Result for problem 2: {compute()}")
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