[New Exercise]: Resistor Color Expert (#54)

* [New Exercise]: Resistor Color Expert

* Update example.gd

* Update test suite and example

config.json

@@ -59,6 +59,14 @@
         "prerequisites": [],
         "difficulty": 2
       },
+      {
+        "slug": "resistor-color-expert",
+        "name": "Resistor Color Expert",
+        "uuid": "af806fda-62fa-4eaa-9b38-a1304a4aed61",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 2
+      },
       {
         "uuid": "c3b37c54-cc4e-49a5-a869-cd7700b0e448",
         "slug": "leap",

exercises/practice/resistor-color-expert/.docs/instructions.md

@@ -0,0 +1,79 @@
+# 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 outputs 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 colors.
+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:
+
+| Band_1  | Band_2  | Band_3     | band_4    |
+| ------- | ------- | ---------- | --------- |
+| Value_1 | Value_2 | Multiplier | Tolerance |
+
+Meaning
+
+- 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.
+
+| Band_1  | Band_2  | Band_3  | Band_4     | band_5    |
+| ------- | ------- | ------- | ---------- | --------- |
+| Value_1 | Value_2 | Value_3 | Multiplier | Tolerance |
+
+Meaning
+
+- 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.
+
+This exercise is about translating the resistor band colors into a label:
+
+"... ohms ...%"
+
+So an input 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 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 of "orange", "orange", "blue", "red" should return:
+
+"33 megaohms ±2%"

exercises/practice/resistor-color-expert/.docs/introduction.md

@@ -0,0 +1,10 @@
+# Introduction
+
+If you want to build something using a Raspberry Pi, you'll probably use _resistors_.
+Like the previous `Resistor Color Duo` and `Resistor Color Trio` exercises, you will be translating resistor color bands to human-readable labels.
+
+- 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 acts as a digit of a 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.

exercises/practice/resistor-color-expert/.meta/config.json

@@ -0,0 +1,17 @@
+{
+  "authors": ["glaxxie"],
+  "files": {
+    "solution": [
+      "resistor_color_expert.gd"
+    ],
+    "test": [
+      "resistor_color_expert_test.gd"
+    ],
+    "example": [
+      ".meta/example.gd"
+    ]
+  },
+  "blurb": "Convert color codes as used on resistors with different bands to a human-readable label.",
+  "source": "Based on earlier resistor color exercises made by Erik Schierboom and Maud de Vries",
+  "source_url": "https://github.com/exercism/problem-specifications/issues/1464"
+}

exercises/practice/resistor-color-expert/.meta/example.gd

@@ -0,0 +1,34 @@
+func color_code(colors):
+	var size = colors.size()
+	if size == 1: return "0 ohms"
+
+	var colors_code = ["black", "brown", "red", "orange", "yellow", "green", "blue", "violet", "grey", "white"]
+	var units = {
+		1e9: "gigaohms",
+		1e6: "megaohms",
+		1e3: "kiloohms"
+		}
+	var tolerances = {
+		"grey"   : 0.05,
+		"violet" : 0.1,
+		"blue"   : 0.25,
+		"green"  : 0.5,
+		"brown"  : 1,
+		"red"    : 2,
+		"gold"   : 5,
+		"silver" : 10
+		}
+
+	var total = 0
+	var magnitute = pow(10, colors_code.find(colors[-2]))
+
+	for i in range(0, size - 2):
+		var color = colors[i]
+		total += colors_code.find(color) * pow(10, (size - i - 3))
+	total *= magnitute
+
+	var tolerance  = tolerances[colors[-1]] #work
+	for key in units.keys():
+		if total >= key:
+			return "%s %s ±%s%%" % [(total / key), units[key], tolerance]
+	return "%s ohms ±%s%%" % [total, tolerance]

exercises/practice/resistor-color-expert/.meta/tests.toml

@@ -0,0 +1,40 @@
+# This is an auto-generated file.
+#
+# Regenerating this file via `configlet sync` will:
+# - Recreate every `description` key/value pair
+# - Recreate every `reimplements` key/value pair, where they exist in problem-specifications
+# - Remove any `include = true` key/value pair (an omitted `include` key implies inclusion)
+# - Preserve any other key/value pair
+#
+# As user-added comments (using the # character) will be removed when this file
+# is regenerated, comments can be added via a `comment` key.
+
+[8c4f9fb6-d477-4250-bc57-b325d2be226f]
+description = "Orange, orange, black, and red"
+
+[d1d4a769-9210-43cc-9a14-6af6ce4c0b00]
+description = "Blue, grey, brown, and violet"
+
+[6af91bc3-8275-4c38-920a-185d30feb5f3]
+description = "Red, black, red, and green"
+
+[9c4630bf-0dda-4212-baca-2f5111530b4d]
+description = "Green, brown, orange, and grey"
+
+[5880ddf1-0dc6-4bd0-b9de-5626117cd2c7]
+description = "One black band"
+
+[a5cfda34-3c02-4bda-b183-726791fb43b2]
+description = "Orange, orange, yellow, black, and brown"
+
+[4f0ad96c-cdab-4c84-95dd-7074e889e001]
+description = "Red, green, yellow, yellow, and brown"
+
+[48c66841-208c-46a7-8992-1e84a2eda9e2]
+description = "Blue, grey, white, brown, and brown"
+
+[4f3aeb0c-fd9d-4cbd-b204-554e61978f73]
+description = "Violet, orange, red, and grey"
+
+[1ae3a17f-8bc0-449c-9831-fddfd2d91c5d]
+description = "Brown, red, orange, green, and blue"

exercises/practice/resistor-color-expert/resistor_color_expert.gd

@@ -0,0 +1,2 @@
+func color_code(colors):
+	pass

exercises/practice/resistor-color-expert/resistor_color_expert_test.gd

@@ -0,0 +1,59 @@
+func test_orange_orange_black_and_red(solution_script):
+	var colors   = ["orange", "orange", "black", "red"]
+	var expected = "33 ohms ±2%"
+	return [expected, solution_script.color_code(colors)]
+
+
+func test_blue_grey_brown_and_violet(solution_script):
+	var colors   = ["blue", "grey", "brown", "violet"]
+	var expected = "680 ohms ±0.1%"
+	return [expected, solution_script.color_code(colors)]
+
+
+func test_red_black_red_and_green(solution_script):
+	var colors   = ["red", "black", "red", "green"]
+	var expected = "2 kiloohms ±0.5%"
+	return [expected, solution_script.color_code(colors)]
+
+
+func test_green_brown_orange_and_grey(solution_script):
+	var colors   = ["green", "brown", "orange", "grey"]
+	var expected = "51 kiloohms ±0.05%"
+	return [expected, solution_script.color_code(colors)]
+
+
+func test_one_black_band(solution_script):
+	var colors   = ["black"]
+	var expected = "0 ohms"
+	return [expected, solution_script.color_code(colors)]
+
+
+func test_orange_orange_yellow_black_and_brown(solution_script):
+	var colors   = ["orange", "orange", "yellow", "black", "brown"]
+	var expected = "334 ohms ±1%"
+	return [expected, solution_script.color_code(colors)]
+
+
+func test_red_green_yellow_yellow_and_brown(solution_script):
+	var colors   = ["red", "green", "yellow", "yellow", "brown"]
+	var expected = "2.54 megaohms ±1%"
+	return [expected, solution_script.color_code(colors)]
+
+
+func test_blue_grey_white_red_and_brown(solution_script):
+	var colors   = ["blue", "grey", "white", "brown", "brown"]
+	var expected = "6.89 kiloohms ±1%"
+	return [expected, solution_script.color_code(colors)]
+
+
+func test_violet_orange_red_and_grey(solution_script):
+	var colors   = ["violet", "orange", "red", "grey"]
+	var expected = "7.3 kiloohms ±0.05%"
+	return [expected, solution_script.color_code(colors)]
+
+
+func test_brown_red_orange_green_and_blue(solution_script):
+	var colors   = ["brown", "red", "orange", "green", "blue"]
+	var expected = "12.3 megaohms ±0.25%"
+	return [expected, solution_script.color_code(colors)]
+