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80 lines
2 KiB
Markdown
80 lines
2 KiB
Markdown
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# Roman Numerals
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Write a function to convert from normal numbers to Roman Numerals.
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The Romans were a clever bunch. They conquered most of Europe and ruled
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it for hundreds of years. They invented concrete and straight roads and
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even bikinis. One thing they never discovered though was the number
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zero. This made writing and dating extensive histories of their exploits
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slightly more challenging, but the system of numbers they came up with
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is still in use today. For example the BBC uses Roman numerals to date
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their programmes.
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The Romans wrote numbers using letters - I, V, X, L, C, D, M. (notice
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these letters have lots of straight lines and are hence easy to hack
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into stone tablets).
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```
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1 => I
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10 => X
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7 => VII
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```
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There is no need to be able to convert numbers larger than about 3000.
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(The Romans themselves didn't tend to go any higher)
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Wikipedia says: Modern Roman numerals ... are written by expressing each
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digit separately starting with the left most digit and skipping any
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digit with a value of zero.
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To see this in practice, consider the example of 1990.
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In Roman numerals 1990 is MCMXC:
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1000=M
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900=CM
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90=XC
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2008 is written as MMVIII:
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2000=MM
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8=VIII
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See also: http://www.novaroma.org/via_romana/numbers.html
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## Elm Installation
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Refer to the [Exercism help page](http://exercism.io/languages/elm) for Elm
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installation and learning resources.
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## Writing the Code
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The first time you start an exercise, you'll need to ensure you have the
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appropriate dependencies installed.
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```bash
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$ npm install
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```
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Execute the tests with:
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```bash
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$ npm test
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```
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Automatically run tests again when you save changes:
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```bash
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$ npm run watch
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```
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As you work your way through the test suite, be sure to remove the `skip <|`
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calls from each test until you get them all passing!
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## Source
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The Roman Numeral Kata [http://codingdojo.org/cgi-bin/index.pl?KataRomanNumerals](http://codingdojo.org/cgi-bin/index.pl?KataRomanNumerals)
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## Submitting Incomplete Solutions
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It's possible to submit an incomplete solution so you can see how others have completed the exercise.
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