crypto_square started

elixir/crypto-square/.exercism/config.json

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+{
+  "authors": [
+    "jimmbraddock"
+  ],
+  "contributors": [
+    "amencarini",
+    "angelikatyborska",
+    "Cohen-Carlisle",
+    "devonestes",
+    "ggpasqualino",
+    "lpil",
+    "neenjaw",
+    "parkerl",
+    "sotojuan",
+    "waiting-for-dev"
+  ],
+  "files": {
+    "solution": [
+      "lib/crypto_square.ex"
+    ],
+    "test": [
+      "test/crypto_square_test.exs"
+    ],
+    "example": [
+      ".meta/example.ex"
+    ]
+  },
+  "blurb": "Implement the classic method for composing secret messages called a square code.",
+  "source": "J Dalbey's Programming Practice problems",
+  "source_url": "https://users.csc.calpoly.edu/~jdalbey/103/Projects/ProgrammingPractice.html"
+}

elixir/crypto-square/.exercism/metadata.json

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+{"track":"elixir","exercise":"crypto-square","id":"1037f974f1844ed2b31c6a84f83a8e18","url":"https://exercism.org/tracks/elixir/exercises/crypto-square","handle":"negrienko","is_requester":true,"auto_approve":false}

elixir/crypto-square/.formatter.exs

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+# Used by "mix format"
+[
+  inputs: ["{mix,.formatter}.exs", "{config,lib,test}/**/*.{ex,exs}"]
+]

elixir/crypto-square/.gitignore

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+# The directory Mix will write compiled artifacts to.
+/_build/
+
+# If you run "mix test --cover", coverage assets end up here.
+/cover/
+
+# The directory Mix downloads your dependencies sources to.
+/deps/
+
+# Where third-party dependencies like ExDoc output generated docs.
+/doc/
+
+# Ignore .fetch files in case you like to edit your project deps locally.
+/.fetch
+
+# If the VM crashes, it generates a dump, let's ignore it too.
+erl_crash.dump
+
+# Also ignore archive artifacts (built via "mix archive.build").
+*.ez
+
+# Ignore package tarball (built via "mix hex.build").
+crypto_square-*.tar
+

elixir/crypto-square/HELP.md

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+# Help
+
+## Running the tests
+
+From the terminal, change to the base directory of the exercise then execute the tests with:
+
+```bash
+$ mix test
+```
+
+This will execute the test file found in the `test` subfolder -- a file ending in `_test.exs`
+
+Documentation:
+
+* [`mix test` - Elixir's test execution tool](https://hexdocs.pm/mix/Mix.Tasks.Test.html)
+* [`ExUnit` - Elixir's unit test library](https://hexdocs.pm/ex_unit/ExUnit.html)
+
+## Pending tests
+
+In test suites of practice exercises, all but the first test have been tagged to be skipped.
+
+Once you get a test passing, you can unskip the next one by commenting out the relevant `@tag :pending` with a `#` symbol.
+
+For example:
+
+```elixir
+# @tag :pending
+test "shouting" do
+  assert Bob.hey("WATCH OUT!") == "Whoa, chill out!"
+end
+```
+
+If you wish to run all tests at once, you can include all skipped test by using the `--include` flag on the `mix test` command:
+
+```bash
+$ mix test --include pending
+```
+
+Or, you can enable all the tests by commenting out the `ExUnit.configure` line in the file `test/test_helper.exs`.
+
+```elixir
+# ExUnit.configure(exclude: :pending, trace: true)
+```
+
+## Useful `mix test` options
+
+* `test/<FILE>.exs:LINENUM` - runs only a single test, the test from `<FILE>.exs` whose definition is on line `LINENUM`
+* `--failed` - runs only tests that failed the last time they ran
+* `--max-failures` - the suite stops evaluating tests when this number of test failures
+is reached
+* `--seed 0` - disables randomization so the tests in a single file will always be ran
+in the same order they were defined in
+
+## Submitting your solution
+
+You can submit your solution using the `exercism submit lib/crypto_square.ex` command.
+This command will upload your solution to the Exercism website and print the solution page's URL.
+
+It's possible to submit an incomplete solution which allows you to:
+
+- See how others have completed the exercise
+- Request help from a mentor
+
+## Need to get help?
+
+If you'd like help solving the exercise, check the following pages:
+
+- The [Elixir track's documentation](https://exercism.org/docs/tracks/elixir)
+- The [Elixir track's programming category on the forum](https://forum.exercism.org/c/programming/elixir)
+- [Exercism's programming category on the forum](https://forum.exercism.org/c/programming/5)
+- The [Frequently Asked Questions](https://exercism.org/docs/using/faqs)
+
+Should those resources not suffice, you could submit your (incomplete) solution to request mentoring.
+
+If you're stuck on something, it may help to look at some of the [available resources](https://exercism.org/docs/tracks/elixir/resources) out there where answers might be found.

elixir/crypto-square/README.md

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+# Crypto Square
+
+Welcome to Crypto Square on Exercism's Elixir Track.
+If you need help running the tests or submitting your code, check out `HELP.md`.
+
+## Instructions
+
+Implement the classic method for composing secret messages called a square code.
+
+Given an English text, output the encoded version of that text.
+
+First, the input is normalized: the spaces and punctuation are removed from the English text and the message is down-cased.
+
+Then, the normalized characters are broken into rows.
+These rows can be regarded as forming a rectangle when printed with intervening newlines.
+
+For example, the sentence
+
+```text
+"If man was meant to stay on the ground, god would have given us roots."
+```
+
+is normalized to:
+
+```text
+"ifmanwasmeanttostayonthegroundgodwouldhavegivenusroots"
+```
+
+The plaintext should be organized into a rectangle as square as possible.
+The size of the rectangle should be decided by the length of the message.
+
+If `c` is the number of columns and `r` is the number of rows, then for the rectangle `r` x `c` find the smallest possible integer `c` such that:
+
+- `r * c >= length of message`,
+- and `c >= r`,
+- and `c - r <= 1`.
+
+Our normalized text is 54 characters long, dictating a rectangle with `c = 8` and `r = 7`:
+
+```text
+"ifmanwas"
+"meanttos"
+"tayonthe"
+"groundgo"
+"dwouldha"
+"vegivenu"
+"sroots  "
+```
+
+The coded message is obtained by reading down the columns going left to right.
+
+The message above is coded as:
+
+```text
+"imtgdvsfearwermayoogoanouuiontnnlvtwttddesaohghnsseoau"
+```
+
+Output the encoded text in chunks that fill perfect rectangles `(r X c)`, with `c` chunks of `r` length, separated by spaces.
+For phrases that are `n` characters short of the perfect rectangle, pad each of the last `n` chunks with a single trailing space.
+
+```text
+"imtgdvs fearwer mayoogo anouuio ntnnlvt wttddes aohghn  sseoau "
+```
+
+Notice that were we to stack these, we could visually decode the ciphertext back in to the original message:
+
+```text
+"imtgdvs"
+"fearwer"
+"mayoogo"
+"anouuio"
+"ntnnlvt"
+"wttddes"
+"aohghn "
+"sseoau "
+```
+
+## Source
+
+### Created by
+
+- @jimmbraddock
+
+### Contributed to by
+
+- @amencarini
+- @angelikatyborska
+- @Cohen-Carlisle
+- @devonestes
+- @ggpasqualino
+- @lpil
+- @neenjaw
+- @parkerl
+- @sotojuan
+- @waiting-for-dev
+
+### Based on
+
+J Dalbey's Programming Practice problems - https://users.csc.calpoly.edu/~jdalbey/103/Projects/ProgrammingPractice.html

elixir/crypto-square/lib/crypto_square.ex

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+defmodule CryptoSquare do
+  @doc """
+  Encode string square methods
+  ## Examples
+
+    iex> CryptoSquare.encode("abcd")
+    "ac bd"
+  """
+  @spec encode(String.t()) :: String.t()
+  def encode(str) do
+    str
+    |> normalize()
+    |> square()
+  end
+
+  defp normalize(str) do
+    str
+    |> String.downcase()
+    |> String.replace(~r/[^a-z0-9]/, "")
+  end
+
+  defp square(str) do
+    length = String.length(str)
+    row = :math.ceil(length ** 0.5)
+    col = :math.ceil(length / row)
+
+    str
+    |> String.split("", trim: true)
+    |> Enum.chunk_every(col, col)
+  end
+end

elixir/crypto-square/mix.exs

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+defmodule CryptoSquare.MixProject do
+  use Mix.Project
+
+  def project do
+    [
+      app: :crypto_square,
+      version: "0.1.0",
+      # elixir: "~> 1.8",
+      start_permanent: Mix.env() == :prod,
+      deps: deps()
+    ]
+  end
+
+  # Run "mix help compile.app" to learn about applications.
+  def application do
+    [
+      extra_applications: [:logger]
+    ]
+  end
+
+  # Run "mix help deps" to learn about dependencies.
+  defp deps do
+    [
+      # {:dep_from_hexpm, "~> 0.3.0"},
+      # {:dep_from_git, git: "https://github.com/elixir-lang/my_dep.git", tag: "0.1.0"}
+    ]
+  end
+end

elixir/crypto-square/test/crypto_square_test.exs

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+defmodule CryptoSquareTest do
+  use ExUnit.Case
+
+  # @tag :pending
+  test "empty plaintext results in an empty ciphertext" do
+    assert CryptoSquare.encode("") == ""
+  end
+
+  @tag :pending
+  test "normalization results in empty plaintext" do
+    assert CryptoSquare.encode("... --- ...") == ""
+  end
+
+  @tag :pending
+  test "lowercase" do
+    assert CryptoSquare.encode("A") == "a"
+  end
+
+  @tag :pending
+  test "remove spaces" do
+    assert CryptoSquare.encode("  b ") == "b"
+  end
+
+  @tag :pending
+  test "remove punctuation" do
+    assert CryptoSquare.encode("@1,%!") == "1"
+  end
+
+  @tag :pending
+  test "9 character plaintext results in 3 chunks of 3 characters" do
+    assert CryptoSquare.encode("This is fun!") == "tsf hiu isn"
+  end
+
+  @tag :pending
+  test "8 character plaintext results in 3 chunks, the last one with a trailing space" do
+    assert CryptoSquare.encode("Chill out.") == "clu hlt io "
+  end
+
+  @tag :pending
+  test "54 character plaintext results in 7 chunks, the last two with trailing spaces" do
+    msg = "If man was meant to stay on the ground, god would have given us roots."
+    cipher = "imtgdvs fearwer mayoogo anouuio ntnnlvt wttddes aohghn  sseoau "
+    assert CryptoSquare.encode(msg) == cipher
+  end
+end

elixir/crypto-square/test/test_helper.exs

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+ExUnit.start()
+ExUnit.configure(exclude: :pending, trace: true)