From 26a8976b52f99e8dee29ea7b5000433bfa2ca13a Mon Sep 17 00:00:00 2001 From: Danylo Negrienko Date: Fri, 28 Jun 2024 18:12:55 -0400 Subject: [PATCH] roman-numbers --- elixir/roman-numerals/.exercism/config.json | 34 ++++++ elixir/roman-numerals/.exercism/metadata.json | 1 + elixir/roman-numerals/.formatter.exs | 4 + elixir/roman-numerals/.gitignore | 24 ++++ elixir/roman-numerals/HELP.md | 75 +++++++++++++ elixir/roman-numerals/README.md | 103 ++++++++++++++++++ elixir/roman-numerals/lib/roman_numerals.ex | 33 ++++++ elixir/roman-numerals/mix.exs | 28 +++++ .../test/roman_numerals_test.exs | 103 ++++++++++++++++++ elixir/roman-numerals/test/test_helper.exs | 2 + 10 files changed, 407 insertions(+) create mode 100644 elixir/roman-numerals/.exercism/config.json create mode 100644 elixir/roman-numerals/.exercism/metadata.json create mode 100644 elixir/roman-numerals/.formatter.exs create mode 100644 elixir/roman-numerals/.gitignore create mode 100644 elixir/roman-numerals/HELP.md create mode 100644 elixir/roman-numerals/README.md create mode 100644 elixir/roman-numerals/lib/roman_numerals.ex create mode 100644 elixir/roman-numerals/mix.exs create mode 100644 elixir/roman-numerals/test/roman_numerals_test.exs create mode 100644 elixir/roman-numerals/test/test_helper.exs diff --git a/elixir/roman-numerals/.exercism/config.json b/elixir/roman-numerals/.exercism/config.json new file mode 100644 index 0000000..2c2bfbe --- /dev/null +++ b/elixir/roman-numerals/.exercism/config.json @@ -0,0 +1,34 @@ +{ + "authors": [ + "rubysolo" + ], + "contributors": [ + "andrewsardone", + "angelikatyborska", + "cetinajero", + "Cohen-Carlisle", + "dalexj", + "devonestes", + "jinyeow", + "lpil", + "neenjaw", + "parkerl", + "sotojuan", + "Teapane", + "waiting-for-dev" + ], + "files": { + "solution": [ + "lib/roman_numerals.ex" + ], + "test": [ + "test/roman_numerals_test.exs" + ], + "example": [ + ".meta/example.ex" + ] + }, + "blurb": "Convert modern Arabic numbers into Roman numerals.", + "source": "The Roman Numeral Kata", + "source_url": "https://codingdojo.org/kata/RomanNumerals/" +} diff --git a/elixir/roman-numerals/.exercism/metadata.json b/elixir/roman-numerals/.exercism/metadata.json new file mode 100644 index 0000000..61220b9 --- /dev/null +++ b/elixir/roman-numerals/.exercism/metadata.json @@ -0,0 +1 @@ +{"track":"elixir","exercise":"roman-numerals","id":"a78bab796579451fae7b60be21481bff","url":"https://exercism.org/tracks/elixir/exercises/roman-numerals","handle":"negrienko","is_requester":true,"auto_approve":false} \ No newline at end of file diff --git a/elixir/roman-numerals/.formatter.exs b/elixir/roman-numerals/.formatter.exs new file mode 100644 index 0000000..d2cda26 --- /dev/null +++ b/elixir/roman-numerals/.formatter.exs @@ -0,0 +1,4 @@ +# Used by "mix format" +[ + inputs: ["{mix,.formatter}.exs", "{config,lib,test}/**/*.{ex,exs}"] +] diff --git a/elixir/roman-numerals/.gitignore b/elixir/roman-numerals/.gitignore new file mode 100644 index 0000000..2a676eb --- /dev/null +++ b/elixir/roman-numerals/.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"). +roman_numerals-*.tar + diff --git a/elixir/roman-numerals/HELP.md b/elixir/roman-numerals/HELP.md new file mode 100644 index 0000000..5fabbf9 --- /dev/null +++ b/elixir/roman-numerals/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/roman_numerals.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/roman-numerals/README.md b/elixir/roman-numerals/README.md new file mode 100644 index 0000000..52d8d43 --- /dev/null +++ b/elixir/roman-numerals/README.md @@ -0,0 +1,103 @@ +# Roman Numerals + +Welcome to Roman Numerals on Exercism's Elixir Track. +If you need help running the tests or submitting your code, check out `HELP.md`. + +## Introduction + +Today, most people in the world use Arabic numerals (0–9). +But if you travelled back two thousand years, you'd find that most Europeans were using Roman numerals instead. + +To write a Roman numeral we use the following Latin letters, each of which has a value: + +| M | D | C | L | X | V | I | +| ---- | --- | --- | --- | --- | --- | --- | +| 1000 | 500 | 100 | 50 | 10 | 5 | 1 | + +A Roman numeral is a sequence of these letters, and its value is the sum of the letters' values. +For example, `XVIII` has the value 18 (`10 + 5 + 1 + 1 + 1 = 18`). + +There's one rule that makes things trickier though, and that's that **the same letter cannot be used more than three times in succession**. +That means that we can't express numbers such as 4 with the seemingly natural `IIII`. +Instead, for those numbers, we use a subtraction method between two letters. +So we think of `4` not as `1 + 1 + 1 + 1` but instead as `5 - 1`. +And slightly confusingly to our modern thinking, we write the smaller number first. +This applies only in the following cases: 4 (`IV`), 9 (`IX`), 40 (`XL`), 90 (`XC`), 400 (`CD`) and 900 (`CM`). + +Order matters in Roman numerals! +Letters (and the special compounds above) must be ordered by decreasing value from left to right. + +Here are some examples: + +```text + 105 => CV +---- => -- + 100 => C ++ 5 => V +``` + +```text + 106 => CVI +---- => -- + 100 => C ++ 5 => V ++ 1 => I +``` + +```text + 104 => CIV +---- => --- + 100 => C ++ 4 => IV +``` + +And a final more complex example: + +```text + 1996 => MCMXCVI +----- => ------- + 1000 => M ++ 900 => CM ++ 90 => XC ++ 5 => V ++ 1 => I +``` + +## Instructions + +Your task is to convert a number from Arabic numerals to Roman numerals. + +For this exercise, we are only concerned about traditional Roman numerals, in which the largest number is MMMCMXCIX (or 3,999). + +~~~~exercism/note +There are lots of different ways to convert between Arabic and Roman numerals. +We recommend taking a naive approach first to familiarise yourself with the concept of Roman numerals and then search for more efficient methods. + +Make sure to check out our Deep Dive video at the end to explore the different approaches you can take! +~~~~ + +## Source + +### Created by + +- @rubysolo + +### Contributed to by + +- @andrewsardone +- @angelikatyborska +- @cetinajero +- @Cohen-Carlisle +- @dalexj +- @devonestes +- @jinyeow +- @lpil +- @neenjaw +- @parkerl +- @sotojuan +- @Teapane +- @waiting-for-dev + +### Based on + +The Roman Numeral Kata - https://codingdojo.org/kata/RomanNumerals/ \ No newline at end of file diff --git a/elixir/roman-numerals/lib/roman_numerals.ex b/elixir/roman-numerals/lib/roman_numerals.ex new file mode 100644 index 0000000..062bd44 --- /dev/null +++ b/elixir/roman-numerals/lib/roman_numerals.ex @@ -0,0 +1,33 @@ +defmodule RomanNumerals do + @doc """ + Convert the number to a roman number. + """ + @romans %{ + 1 => ["I", "X", "C", "M"], + 2 => ["II", "XX", "CC", "MM"], + 3 => ["III", "XXX", "CCC", "MMM"], + 4 => ["IV", "XL", "CD"], + 5 => ["V", "L", "D"], + 6 => ["VI", "LX", "DC"], + 7 => ["VII", "LXX", "DCC"], + 8 => ["VIII", "LXXX", "DCCC"], + 9 => ["IX", "XC", "CM"] + } + + @spec numeral(pos_integer) :: String.t() + def numeral(number) do + number + |> Integer.digits() + |> Enum.reverse() + |> Enum.with_index(&to_roman_digit/2) + |> Enum.reverse() + |> Enum.join() + end + + defp to_roman_digit(0, _index), do: "" + defp to_roman_digit(digit, index) do + @romans + |> Map.fetch!(digit) + |> Enum.at(index) + end +end diff --git a/elixir/roman-numerals/mix.exs b/elixir/roman-numerals/mix.exs new file mode 100644 index 0000000..33f5ed5 --- /dev/null +++ b/elixir/roman-numerals/mix.exs @@ -0,0 +1,28 @@ +defmodule RomanNumerals.MixProject do + use Mix.Project + + def project do + [ + app: :roman_numerals, + 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/roman-numerals/test/roman_numerals_test.exs b/elixir/roman-numerals/test/roman_numerals_test.exs new file mode 100644 index 0000000..aa7f0de --- /dev/null +++ b/elixir/roman-numerals/test/roman_numerals_test.exs @@ -0,0 +1,103 @@ +defmodule RomanNumeralsTest do + use ExUnit.Case + + test "1" do + assert RomanNumerals.numeral(1) == "I" + end + + test "2" do + assert RomanNumerals.numeral(2) == "II" + end + + test "3" do + assert RomanNumerals.numeral(3) == "III" + end + + test "4" do + assert RomanNumerals.numeral(4) == "IV" + end + + test "5" do + assert RomanNumerals.numeral(5) == "V" + end + + test "6" do + assert RomanNumerals.numeral(6) == "VI" + end + + test "9" do + assert RomanNumerals.numeral(9) == "IX" + end + + test "16" do + assert RomanNumerals.numeral(16) == "XVI" + end + + test "27" do + assert RomanNumerals.numeral(27) == "XXVII" + end + + test "48" do + assert RomanNumerals.numeral(48) == "XLVIII" + end + + test "59" do + assert RomanNumerals.numeral(59) == "LIX" + end + + test "66" do + assert RomanNumerals.numeral(66) == "LXVI" + end + + test "93" do + assert RomanNumerals.numeral(93) == "XCIII" + end + + test "141" do + assert RomanNumerals.numeral(141) == "CXLI" + end + + test "163" do + assert RomanNumerals.numeral(163) == "CLXIII" + end + + test "402" do + assert RomanNumerals.numeral(402) == "CDII" + end + + test "575" do + assert RomanNumerals.numeral(575) == "DLXXV" + end + + test "666" do + assert RomanNumerals.numeral(666) == "DCLXVI" + end + + test "911" do + assert RomanNumerals.numeral(911) == "CMXI" + end + + test "1024" do + assert RomanNumerals.numeral(1024) == "MXXIV" + end + + test "1666" do + assert RomanNumerals.numeral(1666) == "MDCLXVI" + end + + test "3000" do + assert RomanNumerals.numeral(3000) == "MMM" + end + + test "3001" do + assert RomanNumerals.numeral(3001) == "MMMI" + end + + test "3888" do + assert RomanNumerals.numeral(3888) == "MMMDCCCLXXXVIII" + end + + test "3999" do + assert RomanNumerals.numeral(3999) == "MMMCMXCIX" + end +end diff --git a/elixir/roman-numerals/test/test_helper.exs b/elixir/roman-numerals/test/test_helper.exs new file mode 100644 index 0000000..35fc5bf --- /dev/null +++ b/elixir/roman-numerals/test/test_helper.exs @@ -0,0 +1,2 @@ +ExUnit.start() +ExUnit.configure(exclude: :pending, trace: true)