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100 lines
2.2 KiB
Markdown
100 lines
2.2 KiB
Markdown
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# Say
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Given a number from 0 to 999,999,999,999, spell out that number in English.
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## Step 1
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Handle the basic case of 0 through 99.
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If the input to the program is `22`, then the output should be
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`'twenty-two'`.
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Your program should complain loudly if given a number outside the
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blessed range.
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Some good test cases for this program are:
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- 0
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- 14
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- 50
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- 98
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- -1
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- 100
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### Extension
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If you're on a Mac, shell out to Mac OS X's `say` program to talk out
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loud.
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## Step 2
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Implement breaking a number up into chunks of thousands.
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So `1234567890` should yield a list like 1, 234, 567, and 890, while the
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far simpler `1000` should yield just 1 and 0.
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The program must also report any values that are out of range.
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## Step 3
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Now handle inserting the appropriate scale word between those chunks.
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So `1234567890` should yield `'1 billion 234 million 567 thousand 890'`
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The program must also report any values that are out of range. It's
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fine to stop at "trillion".
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## Step 4
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Put it all together to get nothing but plain English.
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`12345` should give `twelve thousand three hundred forty-five`.
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The program must also report any values that are out of range.
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### Extensions
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Use _and_ (correctly) when spelling out the number in English:
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- 14 becomes "fourteen".
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- 100 becomes "one hundred".
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- 120 becomes "one hundred and twenty".
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- 1002 becomes "one thousand and two".
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- 1323 becomes "one thousand three hundred and twenty-three".
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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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A variation on JavaRanch CattleDrive, exercise 4a [http://www.javaranch.com/say.jsp](http://www.javaranch.com/say.jsp)
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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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