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exercism fetch ruby ocr-numbers

Ocr Numbers

Given a 3 x 4 grid of pipes, underscores, and spaces, determine which number is represented, or whether it is garbled.

Step One

To begin with, convert a simple binary font to a string containing 0 or 1.

The binary font uses pipes and underscores, four rows high and three columns wide.

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     _   #
    | |  # zero.
    |_|  #
         # the fourth row is always blank

Is converted to "0"

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         #
      |  # one.
      |  #
         # (blank fourth row)

Is converted to "1"

If the input is the correct size, but not recognizable, your program should return '?'

If the input is the incorrect size, your program should return an error.

Step Two

Update your program to recognize multi-character binary strings, replacing garbled numbers with ?

Step Three

Update your program to recognize all numbers 0 through 9, both individually and as part of a larger string.

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 _ 
 _|
|_ 

Is converted to "2"

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      _  _     _  _  _  _  _  _  #
    | _| _||_||_ |_   ||_||_|| | # decimal numbers.
    ||_  _|  | _||_|  ||_| _||_| #
                                 # fourth line is always blank

Is converted to "1234567890"

Step Four

Update your program to handle multiple numbers, one per line. When converting several lines, join the lines with commas.

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    _  _ 
  | _| _|
  ||_  _|

    _  _ 
|_||_ |_ 
  | _||_|

 _  _  _ 
  ||_||_|
  ||_| _|

Is converted to "123,456,789"


For installation and learning resources, refer to the exercism help page.

For running the tests provided, you will need the Minitest gem. Open a terminal window and run the following command to install minitest:

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gem install minitest

If you would like color output, you can require 'minitest/pride' in the test file, or note the alternative instruction, below, for running the test file.

In order to run the test, you can run the test file from the exercise directory. For example, if the test suite is called hello_world_test.rb, you can run the following command:

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ruby hello_world_test.rb

To include color from the command line:

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ruby -r minitest/pride hello_world_test.rb

Source

Inspired by the Bank OCR kata http://codingdojo.org/cgi-bin/wiki.pl?KataBankOCR

Submitting Incomplete Solutions

It's possible to submit an incomplete solution so you can see how others have completed the exercise.