Finding anagrams for a given word

Question

Two words are anagrams if one of them has exactly same characters as that of the another word.

Example : Anagram & Nagaram are anagrams

Answer 1

• Reduce the words to - say - lower case (clojure.string/lower-case).
• Classify them (group-by) by letter frequency-map (frequencies).
• Drop the frequency maps,
• ... leaving the collections of anagrams.

(These) are the corresponding functions in the Lisp dialect Clojure.

The whole function can be expressed so:

(defn anagrams [dict]
  (->> dict
       (map clojure.string/lower-case)
       (group-by frequencies)
       vals))

For example,

(anagrams ["Salt" "last" "one" "eon" "plod"])
;(["salt" "last"] ["one" "eon"] ["plod"])

An indexing function that maps each thing to its collection is

(defn index [xss]
  (into {} (for [xs xss, x xs] [x xs])))

So that, for example,

((comp index anagrams) ["Salt" "last" "one" "eon" "plod"])
;{"salt" ["salt" "last"], "last" ["salt" "last"], "one" ["one" "eon"], "eon" ["one" "eon"], "plod" ["plod"]}

... where comp is the functional composition operator.