saracen / bbc-coin-test

BBC Coin Algorithm Test

DEVELOPER ASSESSMENT

Summary

Write a simple application that given a number of pennies will calculate the minimum number of Sterling coins needed to make that amount.

Eg. 123p = 1 x £1, 1 x 20p, 1 x 2p, 1 x 1p

You should be prepared to spend at least two hours on it.

Requirements

• Account for only the common £2, £1, 50p, 20p, 2p and 1p coins. Ignore those commemorative £5 coins.
• You MUST use JavaScript (node.js is allowed too!), CSS and HTML to do this.
• The user interface should consist of a input field that accepts an 'amount' string (Eg. 92p, £2.12) and displays the denominations needed when the user hits 'enter'.
• Include any instructions, libraries, build files in order for us to run & view your code.
• If you run out of time include a note of things you would like to have done in a README file.

What we are looking for

• High quality and maintainable code.
• Accessible, semantic, valid HTML.
• Unobtrusive JavaScript.
• Test cases for your code (Eg, Qunit, Jasmine), written first!
• Well documented and commented code.
• Follow coding standards.
• Extensible user input parsing and validation.
• To sensibly separate functionality (Eg, input, models, utils, views) following OO patterns.
• Clean visual design.

Test Data

Our business analyst has given us some test data to help you understand the expected user input to this application.

In the first column is a string of user input, and in the second the desired integer expressed as pence.

| input | pence (canonical) | description |
| 4 | 4 | single digit |
| 85 | 85 | double digit |
| 197p | 197 | pence symbol |
| 2p | 2 | pence symbol single digit |
| 1.87 | 187 | pounds decimal |
| £1.23 | 123 | pound symbol |
| £2 | 200 | single digit pound symbol |
| £10 | 1000 | double digit pound symbol |
| £1.87p | 187 | pound and pence symbol |
| £1p | 100 | missing pence |
| £1.p | 100 | missing pence but present decimal point |
| 001.41p | 141 | buffered zeros |
| 4.235p | 424 | rounding three decimal places to two |
| £1.257422457p | 126 | rounding with symbols |

Likewise, the application should not accept the following inputs,

| input | pence (canonical) | description |
| | 0 | empty string |
| 1x | 0 | non-numeric character |
| £1x.0p | 0 | non-numeric character |
| £p | 0 | missing digits |