Given a non-empty list of integers, every element appears twice except for one. Find that single one

[Ted]

And thank you for asking a related question, otherwise using :reduce wouldn’t have come to mind.

Count the number of non-numeric characters in a string and then sum their values

Hello. Trying to solve this problem I wrote the following algorithm: string = "3340c9571y40m47ku49t9315mrvzqo667k36e" # %{ # "c" => 1, # "e" => 1, # "k" => 2, # "m" => 2, # "o" => 1, # "q" => 1, # "r" => 1, # "t" => 1, # "u" => 1, # "v" => 1, # "y" => 1, # "z" => 1 # } # [1, 1, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1] # Expected result => 14 def is_numeric?(char) do Regex.match?(~r/^\d+$/, char) end def total_non_numeric_chars(string) do String.codepoints(string) |> Enum.redu…