53 lines
981 B
Julia
53 lines
981 B
Julia
#=
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Created on 15 Aug 2021
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@author: David Doblas Jiménez
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@email: daviddoji@pm.me
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Solution for Problem 25 of Project Euler
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https://projecteuler.net/problem=25
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=#
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function Problem25()
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#=
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The Fibonacci sequence is defined by the recurrence relation:
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Fn = Fn−1 + Fn−2, where F1 = 1 and F2 = 1.
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Hence the first 12 terms will be:
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F1 = 1
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F2 = 1
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F3 = 2
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F4 = 3
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F5 = 5
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F6 = 8
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F7 = 13
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F8 = 21
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F9 = 34
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F10 = 55
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F11 = 89
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F12 = 144
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The 12th term, F12, is the first term to contain three digits.
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What is the index of the first term in the Fibonacci sequence to
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contain 1000 digits?
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=#
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a, b = 1, 1
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index = 2
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while length(digits(b)) < 1000
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a, b = big(b), big(b+a)
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index += 1
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end
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return index
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end
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println("Time to evaluate Problem 25:")
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@time Problem25()
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println("")
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println("Result for Problem 25: ", Problem25())
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