Avatar of blancohugo

blancohugo's solution

to Anagram in the Clojure Track

Published at Sep 12 2019 · 1 comment
Instructions
Test suite
Solution

Given a word and a list of possible anagrams, select the correct sublist.

Given "listen" and a list of candidates like "enlists" "google" "inlets" "banana" the program should return a list containing "inlets".

Source

Inspired by the Extreme Startup game https://github.com/rchatley/extreme_startup

Submitting Incomplete Solutions

It's possible to submit an incomplete solution so you can see how others have completed the exercise.

anagram_test.clj

(ns anagram-test
  (:require [clojure.test :refer [deftest is]]
            anagram))

(deftest no-matches
  (is (= []
         (anagram/anagrams-for "diaper" ["hello" "world" "zombies" "pants"]))))

(deftest detect-simple-anagram
  (is (= ["tan"] (anagram/anagrams-for "ant" ["tan" "stand" "at"]))))

(deftest does-not-confuse-different-duplicates
  (is (= [] (anagram/anagrams-for "galea" ["eagle"]))))

(deftest eliminate-anagram-subsets
  (is (= [] (anagram/anagrams-for "good" ["dog" "goody"]))))

(deftest detect-anagram
  (is (= ["inlets"]
         (let [coll ["enlists" "google" "inlets" "banana"]]
           (anagram/anagrams-for "listen" coll)))))

(deftest multiple-anagrams
  (is (= ["gallery" "regally" "largely"]
         (let [coll ["gallery" "ballerina" "regally"
                     "clergy"  "largely"   "leading"]]
           (anagram/anagrams-for "allergy" coll)))))

(deftest case-insensitive-anagrams
  (is (= ["Carthorse"]
         (let [coll ["cashregister" "Carthorse" "radishes"]]
           (anagram/anagrams-for "Orchestra" coll)))))

(deftest word-is-not-own-anagram
  (is (= [] (anagram/anagrams-for "banana" ["banana"]))))

(deftest capital-word-is-not-own-anagram
  (is (= [] (anagram/anagrams-for "BANANA" ["banana"]))))
(ns anagram
  (:require [clojure.string :as str]))

(defn remove-char [word index]
  (cond
    (>= index (count word)) word
    (empty? word) word
    :else (str (subs word 0 index)
               (subs word (inc index)))))

(defn extract-letters [word letters]
  (if (empty? letters)
    word
    (let [index (str/index-of word (first letters))]
      (if index
        (recur (remove-char word index) (rest letters))
        (recur word (rest letters))))))

(defn anagram? [word prospect]
  (let [word (str/lower-case word)
        prospect (str/lower-case prospect)]
    (cond
      (or (empty? word) (empty? prospect)) false
      (= word prospect) false
      :else (and (empty? (extract-letters word (seq prospect)))
                 (empty? (extract-letters prospect (seq word)))))))

(defn anagrams-for [word prospect-list]
  (filter #(anagram? word %) prospect-list))

Community comments

Find this solution interesting? Ask the author a question to learn more.
Avatar of blancohugo

I just realized that I could have done this with frequencies.

What can you learn from this solution?

A huge amount can be learned from reading other people’s code. This is why we wanted to give exercism users the option of making their solutions public.

Here are some questions to help you reflect on this solution and learn the most from it.

  • What compromises have been made?
  • Are there new concepts here that you could read more about to improve your understanding?