Resistor Color Expert

Instructions

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 1, 4, or 5 colors as input and output the correct value in ohms. The color bands are encoded as follows:

• black: 0
• brown: 1
• red: 2
• orange: 3
• yellow: 4
• green: 5
• blue: 6
• violet: 7
• grey: 8
• white: 9

In Resistor Color Trio you decoded the first three color bands. For instance: orange-orange-brown translated to the main value 330. In this exercise you will need to add tolerance to the mix. Tolerance is the maximum amount that a value can be above or below the main value. For example, if the last band is green, the maximum tolerance will be ±0.5%.

The tolerance band will have one of these values:

• grey - 0.05%
• violet - 0.1%
• blue - 0.25%
• green - 0.5%
• brown - 1%
• red - 2%
• gold - 5%
• silver - 10%

The four-band resistor is built up like this:

Examples:

• orange-orange-brown-green would be 330 ohms with a ±0.5% tolerance.
• orange-orange-red-grey would be 3300 ohms with ±0.05% tolerance.

The difference between a four and five-band resistor is that the five-band resistor has an extra band to indicate a more precise value.

Examples:

• orange-orange-orange-black-green would be 333 ohms with a ±0.5% tolerance.
• orange-red-orange-blue-violet would be 323M ohms with a ±0.10 tolerance.

There are also one band resistors. One band resistors only have the color black with a value of 0.

Your program should translate an input list of resistor band colors into a label:

"... ohms ...%"

So an input list of ["orange", "orange", "black", "green"] should return:

"33 ohms ±0.5%"

When there are more than a thousand ohms, we say "kiloohms". That's similar to saying "kilometer" for 1000 meters, and "kilograms" for 1000 grams.

So an input list of ["orange", "orange", "orange", "grey"] should return:

"33 kiloohms ±0.05%"

When there are more than a million ohms, we say "megaohms".

So an input list of ["orange", "orange", "blue", "red"] should return:

"33 megaohms ±2%"

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Source

Based on earlier resistor color exercises made by Erik Schierboom and Maud de Vries