anagram.cr

def find_anagram(word, list)
  small_word = word.downcase
  word_chars = small_word.chars.sort

  list.map(&.downcase) # Only care about downcase'd for now
    .map_with_index{|x, i| {x, i}} # But keep the index
    .reject{|(x, _)| x == small_word} # Throw out equals
    .select{|(x, _)| x.chars.sort == word_chars} # Find anagrams
    .uniq(&.first) # Throw out duplicates
    .map{|(_, i)| list[i]} # Restore case of input word
    .to_a # Done.
end

pp find_anagram "Hello", %w[ olleH Car olleH Hlleo ]
pp find_anagram "Hello", %w[ Car ]