#=
Created on 18 Sep 2021

@author: David Doblas Jiménez
@email: daviddoji@pm.me

Solution for Problem 47 of Project Euler
https://projecteuler.net/problem=47 =#

using BenchmarkTools

function factor(n)
    ans = []
    d = 2
    while d * d <= n
        if n % d == 0
            push!(ans, d)
            n = n ÷ d
        else
            d += 1
        end
    end
    if n > 1
        push!(ans, n)
    end
    return ans
end

function Problem47()
    #=
    The first two consecutive numbers to have two distinct prime factors are:

        14 = 2 × 7
        15 = 3 × 5

    The first three consecutive numbers to have three distinct prime factors are:

        644 = 2² × 7 × 23
        645 = 3 × 5 × 43
        646 = 2 × 17 × 19.

    Find the first four consecutive integers to have four distinct prime factors each.
    What is the first of these numbers? =#
    ans = []

    for number in 1:1_000_000
        if length(ans) == 4
            break
        elseif length(Set(factor(number))) == 4
            push!(ans, number)
        else
            ans = []
        end
    end

    return ans[1]
end


println("Time to evaluate Problem $(lpad(47, 3, "0")):")
@btime Problem47()
println("")
println("Result for Problem $(lpad(47, 3, "0")): ", Problem47())