Solution to problem 27 in Julia
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src/Julia/Problem027.jl
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src/Julia/Problem027.jl
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Created on 19 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 27 of Project Euler
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https://projecteuler.net/problem=27
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=#
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using Primes
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function Problem27()
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#=
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Euler discovered the remarkable quadratic formula:
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n^2 + n + 41
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It turns out that the formula will produce 40 primes for the consecutive
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integer values 0≤n≤39. However, when n=40, 40^2+40+41=40(40+1)+41 is
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divisible by 41, and certainly when n=41,41^2+41+41 is clearly divisible
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by 41.
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The incredible formula n^2−79n+1601 was discovered, which produces 80
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primes for the consecutive values 0≤n≤79. The product of the coefficients,
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−79 and 1601, is −126479.
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Considering quadratics of the form:
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n^2 + an + b
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where |a|<1000, |b|≤1000 and |n| is the modulus/absolute value of n
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e.g. |11|=11 and |−4|=4
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Find the product of the coefficients, a and b, for the quadratic expression
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that produces the maximum number of primes for consecutive values of n,
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starting with n=0.
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=#
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LIMIT = 1000
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consecutive_values = 0
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c = 0
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for a in -999:LIMIT-1
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for b in 0:LIMIT
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n = 0
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while isprime((n^2) + (a * n) + b)
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n += 1
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if n > consecutive_values
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consecutive_values = n
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c = a * b
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end
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end
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end
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end
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return c
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end
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println("Time to evaluate Problem 27:")
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@time Problem27()
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println("")
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println("Result for Problem 27: ", Problem27())
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