Skip to content

Latest commit

 

History

History
44 lines (33 loc) · 1.6 KB

2013-02-26-ruby-review-problem.md

File metadata and controls

44 lines (33 loc) · 1.6 KB
Raw

Ruby Practice Review Problem

LCD Numbers

Write a program that displays scalable, LCD-style numbers. This program should be written as a command line program, and should be called as follows:

ruby lcd.rb 012345
ruby lcd.rb 012345 2 # The second argument is optional; it's the scaling factor (the default should be 2)

The correct display for the previous input should be:

 --        --   --        -- 
|  |    |    |    | |  | |   
|  |    |    |    | |  | |   
           --   --   --   -- 
|  |    | |       |    |    |
|  |    | |       |    |    |
 --        --   --        --

If we scale the numbers by one, the command will be ruby lcd.rb 0123 1, and the output will be as follows:

 -       -   -       - 
| |   |   |   | | | |  
         -   -   -   - 
| |   | |     |   |   |
 -       -   -       -

When scaled to 1, it should look like a seven-segment LCD digit. Scaling by n means that the hyphens should be duplicated n times, and the lines with | should be repeated n times.

LCD Numbers Hint

  • Consider using a template for each digit that holds the digit's LCD representation at a scale of 1. Combine this with gsub or sub as well as index to manipulate the templates.
  • Alternatively, take the more digital approach, rather than string manipulation, and represent the presence of each of the seven segments as on or off in a bit vector.