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shmibs's solution

to Anagram in the Crystal Track

Published at Nov 21 2018 · 0 comments
Instructions
Test suite
Solution

Note:

This exercise has changed since this solution was written.

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".

Setup

Follow the setup instructions for Crystal here:

http://exercism.io/languages/crystal

More help installing can be found here:

http://crystal-lang.org/docs/installation/index.html

Making the Test Suit Pass

Execute the tests with:

$ crystal spec

In each test suite all but the first test have been skipped.

Once you get a test passing, you can unskip the next one by changing pending to it.

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_spec.cr

require "spec"
require "../src/*"

describe "Anagram" do
  describe "#find" do
    it "detects no anagrams" do
      Anagram.find("diaper", ["hello", "world", "zombies", "pants"]).should eq [] of String
    end

    pending "detects one anagram" do
      Anagram.find("ant", ["tan", "stand", "at"]).should eq ["tan"]
    end

    pending "detects multiple anagrams" do
      Anagram.find("master", ["stream", "pigeon", "maters"]).should eq ["stream", "maters"]
    end

    pending "detects multiple anagrams 2" do
      Anagram.find("allergy", ["gallery", "ballerina", "regally", "clergy", "largely", "leading"]).should eq ["gallery", "regally", "largely"]
    end

    pending "does not detect false positives" do
      Anagram.find("galea", ["eagle"]).should eq [] of String
    end

    pending "does not detect anagram subsets" do
      Anagram.find("good", ["dog", "goody"]).should eq [] of String
    end

    pending "does not detect identical words" do
      Anagram.find("corn", ["corn", "dark", "Corn", "rank", "CORN", "cron", "park"]).should eq ["cron"]
    end

    pending "detects anagrams case-insensitively" do
      Anagram.find("Orchestra", ["cashregister", "carthorse", "radishes"]).should eq ["carthorse"]
    end

    pending "does not detect a word as its own anagram" do
      Anagram.find("banana", ["Banana"]).should eq [] of String
    end

    pending "anagrams must use all letters exactly once" do
      Anagram.find("tapper", ["patter"]).should eq [] of String
    end
  end
end
module Anagram
  extend self

  def find(str, li)
    str = str.downcase
    sorted = str.chars.sort!

    li.select { |s|
      s = s.downcase
      str != s && sorted == s.chars.sort!
    }
  end

end

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