CodingGame - Mime Type(easy)

https://www.codingame.com/ide/puzzle/mime-type
最大的卡住是在有一題他會給你”“.mp3.”
我本來以為用split(‘.’)他會拆成

["", "mp3", ""]

結果是這樣

["", "mp3"]

要在後面加-1才會變成我心目中以為的樣子
http://ruby-doc.org/core-2.3.1/String.html#method-i-split

fname.split('.', -1)

---

@n = gets.to_i # Number of elements which make up the association table.
@q = gets.to_i # Number Q of file names to be analyzed.
list = {}
@n.times do
    # ext: file extension
    # mt: MIME type.
    ext, mt = gets.split(" ")
    list[ext.downcase] = mt
end
# STDERR.puts ext2, mt2
STDERR.puts list

@q.times do |i|
    fname = gets.chomp # One file name per line.
    fname_ext = fname.split('.', -1)[-1].downcase
    STDERR.puts "fname " + fname
    if fname.split('.').size != 1

        if list.has_key?(fname_ext)
            puts list[fname_ext]
        else

            puts "UNKNOWN"
        end
    else
        puts "UNKNOWN"
    end
end

上面是我的解答,就很普通的那種XD
後來看別人寫的

@q.times do
    puts @map[File.extname("x#{gets.chomp}").gsub('.', '').downcase]
end

原來有extname可以直接抓副檔名阿…………
https://ruby-doc.org/core-2.2.0/File.html

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