Palindrome

Mix.install([
  {:jason, "~> 1.4"},
  {:kino, "~> 0.8.0", override: true},
  {:youtube, github: "brooklinjazz/youtube"},
  {:hidden_cell, github: "brooklinjazz/hidden_cell"}
])

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Palindrome

A word or sentence that reads the same way forwards and backwards is a palindrome. For example kayak and racecar are palindromes.

You’re going to create a Palindrome module which can determine if a string is a palindrome.

Palindrome.palindrome?("kayak")
true

Example Solution

defmodule Palindrome do
  def palindrome?(string) do
    string
    |> String.split("")
    |> Enum.reverse()
    |> Enum.join() == string
  end
end

Implement the Palindrome module as documented below.

defmodule Palindrome do
  @moduledoc """
  Documentation for `Palindrome`.
  """

  @doc """
  Determine if two strings are anagrams.

  ## Examples

    iex> Palindrome.palindrome?("baab")
    true

    iex> Palindrome.palindrome?("racecar")
    true

    iex> Palindrome.palindrome?("kayak")
    true

    iex> Palindrome.palindrome?("apples")
    false
  """
  def palindrome?(string) do
  end
end

Mark As Completed

file_name = Path.basename(Regex.replace(~r/#.+/, __ENV__.file, ""), ".livemd")

save_name =
  case Path.basename(__DIR__) do
    "reading" -> "palindrome_reading"
    "exercises" -> "palindrome_exercise"
  end

progress_path = __DIR__ <> "/../progress.json"
existing_progress = File.read!(progress_path) |> Jason.decode!()

default = Map.get(existing_progress, save_name, false)

form =
  Kino.Control.form(
    [
      completed: input = Kino.Input.checkbox("Mark As Completed", default: default)
    ],
    report_changes: true
  )

Task.async(fn ->
  for %{data: %{completed: completed}} <- Kino.Control.stream(form) do
    File.write!(
      progress_path,
      Jason.encode!(Map.put(existing_progress, save_name, completed), pretty: true)
    )
  end
end)

form

Commit Your Progress

Run the following in your command line from the curriculum folder to track and save your progress in a Git commit. Ensure that you do not already have undesired or unrelated changes by running git status or by checking the source control tab in Visual Studio Code.

$ git checkout -b palindrome-exercise
$ git add .
$ git commit -m "finish palindrome exercise"
$ git push origin palindrome-exercise

Create a pull request from your palindrome-exercise branch to your solutions branch. Please do not create a pull request to the DockYard Academy repository as this will spam our PR tracker.

DockYard Academy Students Only:

Notify your teacher by including @BrooklinJazz in your PR description to get feedback. You (or your teacher) may merge your PR into your solutions branch after review.

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