Project Euler - 22

Names scores

Using names.txt (right click and 'Save Link/Target As...'), a 46K text
file containing over five-thousand first names, begin by sorting it
into alphabetical order. Then working out the alphabetical value for
each name, multiply this value by its alphabetical position in the
list to obtain a name score.

For example, when the list is sorted into alphabetical order, COLIN,
which is worth $3 + 15 + 12 + 9 + 14 = 53$, is the 938th name in the
list. So, COLIN would obtain a score of $938 × 53 = 49714$.

What is the total of all the name scores in the file?

While being fairly comfortable with the zen of Python, Julia is very new to me. Is the following code in line with Julia's vision?

In particular I feel my handling of the dictionary is sub-optimal and especially the way i hard-code remove the parenthesis in names.

Every hint on how to improve the code is welcome.

ALPHABET_INDEX = Dict( letter => index for (index, letter) in enumerate('A':'Z'))



function namescore(name)

    return sum(ALPHABET_INDEX[letter] for letter in name[2:end-1])

end





function sort_file(filename)

    file = open(filename)

    sort(split(readstring(filename),","))

end





function PE_022(filename="p022_names.txt")



    total = 0

    for (index, name) in enumerate(sort_file(filename))

        total += index*namescore(name)

    end

    total

end



println(PE_022())

the only change I would make is to remove your use of the Dict. Dicts are great when you need mutability, but here there is the much simpler solution Int(letter)-Int('A'). With this change, namescore becomes

function namescore(name)

    return sum(Int(char)-Int('A') for letter in name[2:end-1])

end

This, however is not ideal, as we can take out the subtraction, yielding

function namescore(name)

    return sum(Int(char) for letter in name[2:end-1]) - (lenth(name)-2) * Int('A')

end

I haven't done performance testing, but this should be a fair bit faster, as I would expect Int to be faster than a dictionary lookup.

I solved the same problem a few months ago, here's the code I used:

name_scores_total() = name_scores_total(@__DIR__()*"/022data_names.txt")

name_scores_total(names_file::String) = name_scores_total(vec(readdlm(names_file, ',', String)))



function name_scores_total(names_list::Array{String})

    sort!(names_list)

    alphabet_order = Dict((c, UInt8(c) - UInt8('A') + 1) for c in 'A':'Z')



    total_score = 0

    for (pos, name) in enumerate(names_list)

        try

            name_score = pos * sum(alphabet_order[c] for c in name)

            total_score += name_score

        catch er

            er isa KeyError && error("Only CAPITAL English letters are allowed in the file ($(name) has $(er.key) in it)")

            rethrow()

        end

    end



    total_score

end



if !isinteractive()

    println(name_scores_total())

end

Pretty similar to what your code does when it comes down to it (the main loop), but uses multiple dispatch to allow different types of input, and uses readdlm to read the file, which automatically strips the quotes around the input fields.

I can't say for sure that this is a "better" way of doing things since I'm also still getting a feel for the language, but at the least it just offers a different approach.