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Resistor Color Duo
Resistor Color Duo

Resistor Color Duo

Easy

Instructions

If you want to build something using a Raspberry Pi, you'll probably use resistors. For this exercise, you need to know two things about them:

  • Each resistor has a resistance value.
  • Resistors are small - so small in fact that if you printed the resistance value on them, it would be hard to read.

To get around this problem, manufacturers print color-coded bands onto the resistors to denote their resistance values. Each band has a position and a numeric value.

The first 2 bands of a resistor have a simple encoding scheme: each color maps to a single number. For example, if they printed a brown band (value 1) followed by a green band (value 5), it would translate to the number 15.

In this exercise you are going to create a helpful program so that you don't have to remember the values of the bands. The program will take color names as input and output a two digit number, even if the input is more than two colors!

The band colors are encoded as follows:

  • Black: 0
  • Brown: 1
  • Red: 2
  • Orange: 3
  • Yellow: 4
  • Green: 5
  • Blue: 6
  • Violet: 7
  • Grey: 8
  • White: 9

From the example above: brown-green should return 15 brown-green-violet should return 15 too, ignoring the third color.

Last updated 21 October 2021
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