From 9adeef7c61e1d2066211277259ace95745a26ae9 Mon Sep 17 00:00:00 2001 From: Danylo Negrienko Date: Sat, 29 Jun 2024 00:20:33 -0400 Subject: [PATCH] rotaitional_chiper --- .../rotational-cipher/.exercism/config.json | 26 +++++++ .../rotational-cipher/.exercism/metadata.json | 1 + elixir/rotational-cipher/.formatter.exs | 4 + elixir/rotational-cipher/.gitignore | 24 ++++++ elixir/rotational-cipher/HELP.md | 75 +++++++++++++++++++ elixir/rotational-cipher/README.md | 52 +++++++++++++ .../lib/rotational_cipher.ex | 60 +++++++++++++++ elixir/rotational-cipher/mix.exs | 28 +++++++ .../test/rotational_cipher_test.exs | 65 ++++++++++++++++ elixir/rotational-cipher/test/test_helper.exs | 2 + 10 files changed, 337 insertions(+) create mode 100644 elixir/rotational-cipher/.exercism/config.json create mode 100644 elixir/rotational-cipher/.exercism/metadata.json create mode 100644 elixir/rotational-cipher/.formatter.exs create mode 100644 elixir/rotational-cipher/.gitignore create mode 100644 elixir/rotational-cipher/HELP.md create mode 100644 elixir/rotational-cipher/README.md create mode 100644 elixir/rotational-cipher/lib/rotational_cipher.ex create mode 100644 elixir/rotational-cipher/mix.exs create mode 100644 elixir/rotational-cipher/test/rotational_cipher_test.exs create mode 100644 elixir/rotational-cipher/test/test_helper.exs diff --git a/elixir/rotational-cipher/.exercism/config.json b/elixir/rotational-cipher/.exercism/config.json new file mode 100644 index 0000000..c0aac2b --- /dev/null +++ b/elixir/rotational-cipher/.exercism/config.json @@ -0,0 +1,26 @@ +{ + "authors": [ + "DoggettCK" + ], + "contributors": [ + "angelikatyborska", + "Cohen-Carlisle", + "devonestes", + "neenjaw", + "sotojuan" + ], + "files": { + "solution": [ + "lib/rotational_cipher.ex" + ], + "test": [ + "test/rotational_cipher_test.exs" + ], + "example": [ + ".meta/example.ex" + ] + }, + "blurb": "Create an implementation of the rotational cipher, also sometimes called the Caesar cipher.", + "source": "Wikipedia", + "source_url": "https://en.wikipedia.org/wiki/Caesar_cipher" +} diff --git a/elixir/rotational-cipher/.exercism/metadata.json b/elixir/rotational-cipher/.exercism/metadata.json new file mode 100644 index 0000000..ed6416e --- /dev/null +++ b/elixir/rotational-cipher/.exercism/metadata.json @@ -0,0 +1 @@ +{"track":"elixir","exercise":"rotational-cipher","id":"bd76a5d1822947e48b10bad622ce9d75","url":"https://exercism.org/tracks/elixir/exercises/rotational-cipher","handle":"negrienko","is_requester":true,"auto_approve":false} \ No newline at end of file diff --git a/elixir/rotational-cipher/.formatter.exs b/elixir/rotational-cipher/.formatter.exs new file mode 100644 index 0000000..d2cda26 --- /dev/null +++ b/elixir/rotational-cipher/.formatter.exs @@ -0,0 +1,4 @@ +# Used by "mix format" +[ + inputs: ["{mix,.formatter}.exs", "{config,lib,test}/**/*.{ex,exs}"] +] diff --git a/elixir/rotational-cipher/.gitignore b/elixir/rotational-cipher/.gitignore new file mode 100644 index 0000000..47173e8 --- /dev/null +++ b/elixir/rotational-cipher/.gitignore @@ -0,0 +1,24 @@ +# 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"). +rotational_cipher-*.tar + diff --git a/elixir/rotational-cipher/HELP.md b/elixir/rotational-cipher/HELP.md new file mode 100644 index 0000000..eaf835b --- /dev/null +++ b/elixir/rotational-cipher/HELP.md @@ -0,0 +1,75 @@ +# 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/.exs:LINENUM` - runs only a single test, the test from `.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/rotational_cipher.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. \ No newline at end of file diff --git a/elixir/rotational-cipher/README.md b/elixir/rotational-cipher/README.md new file mode 100644 index 0000000..bb723ce --- /dev/null +++ b/elixir/rotational-cipher/README.md @@ -0,0 +1,52 @@ +# Rotational Cipher + +Welcome to Rotational Cipher on Exercism's Elixir Track. +If you need help running the tests or submitting your code, check out `HELP.md`. + +## Instructions + +Create an implementation of the rotational cipher, also sometimes called the Caesar cipher. + +The Caesar cipher is a simple shift cipher that relies on transposing all the letters in the alphabet using an integer key between `0` and `26`. +Using a key of `0` or `26` will always yield the same output due to modular arithmetic. +The letter is shifted for as many values as the value of the key. + +The general notation for rotational ciphers is `ROT + `. +The most commonly used rotational cipher is `ROT13`. + +A `ROT13` on the Latin alphabet would be as follows: + +```text +Plain: abcdefghijklmnopqrstuvwxyz +Cipher: nopqrstuvwxyzabcdefghijklm +``` + +It is stronger than the Atbash cipher because it has 27 possible keys, and 25 usable keys. + +Ciphertext is written out in the same formatting as the input including spaces and punctuation. + +## Examples + +- ROT5 `omg` gives `trl` +- ROT0 `c` gives `c` +- ROT26 `Cool` gives `Cool` +- ROT13 `The quick brown fox jumps over the lazy dog.` gives `Gur dhvpx oebja sbk whzcf bire gur ynml qbt.` +- ROT13 `Gur dhvpx oebja sbk whzcf bire gur ynml qbt.` gives `The quick brown fox jumps over the lazy dog.` + +## Source + +### Created by + +- @DoggettCK + +### Contributed to by + +- @angelikatyborska +- @Cohen-Carlisle +- @devonestes +- @neenjaw +- @sotojuan + +### Based on + +Wikipedia - https://en.wikipedia.org/wiki/Caesar_cipher \ No newline at end of file diff --git a/elixir/rotational-cipher/lib/rotational_cipher.ex b/elixir/rotational-cipher/lib/rotational_cipher.ex new file mode 100644 index 0000000..a00ba8c --- /dev/null +++ b/elixir/rotational-cipher/lib/rotational_cipher.ex @@ -0,0 +1,60 @@ +defmodule RotationalCipher do + @moduledoc """ + Generates a simple Caesar cipher by rotating the alphabet by a given amount. + Use for that shifted alphabet generation function and transliteration table based on two alphabets. + """ + + @alphabet ?a..?z + |> Enum.to_list() + |> to_string() + |> String.split("", trim: true) + + # Generates a shifted alphabet based on the given shift amount. + # If swaped is true, the function will return a map with the index as the key and the character as the value, + # otherwise the function will return a map with the character as the key and the index as the value. + + defp alphabet(shift \\ 0, swaped \\ false) when shift < 26 and shift >= 0 do + @alphabet + |> Enum.with_index(fn char, index -> + position = if index + shift >= 26, do: index + shift - 26, else: index + shift + if swaped == true, do: {position, char}, else: {char, position} + end) + |> Enum.into(%{}) + end + + # Generates a transliteration table based on the given shift amount. + + defp transliterate_table(shift) do + transliterated = alphabet(shift, true) + + alphabet() + |> Enum.reduce(%{}, fn {char, index}, acc -> + Map.merge(acc, %{ + transliterated[index] => char, + String.upcase(transliterated[index]) => String.upcase(char) + }) + end) + end + + defp rotate_char(char, table), do: table[char] || char + + @doc """ + Given a plaintext and amount to shift by, return a rotated string. + + Example: + iex> RotationalCipher.rotate("Attack at dawn", 13) + "Nggnpx ng qnja" + """ + + @spec rotate(text :: String.t(), shift :: integer) :: String.t() + def rotate(text, shift) when shift == 0 or shift == 26, do: text + + def rotate(text, shift) do + table = transliterate_table(shift) + + text + |> String.graphemes() + |> Enum.map(&rotate_char(&1, table)) + |> Enum.join() + end +end diff --git a/elixir/rotational-cipher/mix.exs b/elixir/rotational-cipher/mix.exs new file mode 100644 index 0000000..ffa4264 --- /dev/null +++ b/elixir/rotational-cipher/mix.exs @@ -0,0 +1,28 @@ +defmodule RotationalCipher.MixProject do + use Mix.Project + + def project do + [ + app: :rotational_cipher, + 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 diff --git a/elixir/rotational-cipher/test/rotational_cipher_test.exs b/elixir/rotational-cipher/test/rotational_cipher_test.exs new file mode 100644 index 0000000..5e93853 --- /dev/null +++ b/elixir/rotational-cipher/test/rotational_cipher_test.exs @@ -0,0 +1,65 @@ +defmodule RotationalCipherTest do + use ExUnit.Case + + test "rotate a by 1" do + plaintext = "a" + shift = 1 + assert RotationalCipher.rotate(plaintext, shift) == "b" + end + + test "rotate a by 26, same output as input" do + plaintext = "a" + shift = 26 + assert RotationalCipher.rotate(plaintext, shift) == "a" + end + + test "rotate a by 0, same output as input" do + plaintext = "a" + shift = 0 + assert RotationalCipher.rotate(plaintext, shift) == "a" + end + + test "rotate m by 13" do + plaintext = "m" + shift = 13 + assert RotationalCipher.rotate(plaintext, shift) == "z" + end + + test "rotate n by 13 with wrap around alphabet" do + plaintext = "n" + shift = 13 + assert RotationalCipher.rotate(plaintext, shift) == "a" + end + + test "rotate capital letters" do + plaintext = "OMG" + shift = 5 + assert RotationalCipher.rotate(plaintext, shift) == "TRL" + end + + test "rotate spaces" do + plaintext = "O M G" + shift = 5 + assert RotationalCipher.rotate(plaintext, shift) == "T R L" + end + + test "rotate numbers" do + plaintext = "Testing 1 2 3 testing" + shift = 4 + assert RotationalCipher.rotate(plaintext, shift) == "Xiwxmrk 1 2 3 xiwxmrk" + end + + test "rotate punctuation" do + plaintext = "Let's eat, Grandma!" + shift = 21 + assert RotationalCipher.rotate(plaintext, shift) == "Gzo'n zvo, Bmviyhv!" + end + + test "rotate all letters" do + plaintext = "The quick brown fox jumps over the lazy dog." + shift = 13 + + assert RotationalCipher.rotate(plaintext, shift) == + "Gur dhvpx oebja sbk whzcf bire gur ynml qbt." + end +end diff --git a/elixir/rotational-cipher/test/test_helper.exs b/elixir/rotational-cipher/test/test_helper.exs new file mode 100644 index 0000000..35fc5bf --- /dev/null +++ b/elixir/rotational-cipher/test/test_helper.exs @@ -0,0 +1,2 @@ +ExUnit.start() +ExUnit.configure(exclude: :pending, trace: true)