Roman numerals are I, V, X, L, C, D, and M. They correspond to the common (Hindu-Arabic) numbers 1, 5, 10, 50, 100, 500, and 1000, respectively.
Roman numbers are written using these numerals; and are additive in all cases except when I precedes V or X, X precedes L or C, and C precedes D or M.
In these cases, the smaller Roman number is subtracted from the former, viz:
- IV = 4
- IX = 9
- XL = 40
- XC = 90
- CD = 400
- CM = 900
This monorepo contains a few TDD'd samples of Roman to Hindu-Arabic conversions. The purpose is illustrative: how TDD aids in simple design and refactoring.
It's instructive to examine not just the final solution but each individual commit.
This is a monorepo. When you clone it, you'll get small codebases in multiple languages.
Make sure you have node.js installed.
Then, in a shell/terminal window, cd to the js directory and run yarn install followed by yarn run test.
Make sure you have Ruby installed.
Install the bundler gem by running gem install bundler in a shell/terminal window.
Then, in a shell/terminal window, cd to the ruby directory and run ruby test_roman.rb.
Make sure you have Kotlin installed
Linux / MacOS: In a shell/terminal window, cd to the kotlin directory and run ./gradlew init followed by ./gradlew test
Windows: In a cmd window, cd to the kotlin directory and run gradlew.bat init followed by gradlew.bat test
https://en.wikipedia.org/wiki/Roman_numerals
https://en.wikipedia.org/wiki/Hindu%E2%80%93Arabic_numeral_system