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keiravillekodekeiravillekode
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Add prime-factors exercise (#60)
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‎config.json‎

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"prerequisites": [],
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"difficulty": 3
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},
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{
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"slug": "prime-factors",
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"name": "Prime Factors",
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"uuid": "666dbc7f-a9a0-444b-9e3a-ebe9bc53fc6b",
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"practices": [],
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"prerequisites": [],
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"difficulty": 3
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},
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{
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"slug": "protein-translation",
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"name": "Protein Translation",

‎exercises/practice/prime-factors/.docs/instructions.md‎

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# Instructions
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Compute the prime factors of a given natural number.
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A prime number is only evenly divisible by itself and 1.
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Note that 1 is not a prime number.
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## Example
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What are the prime factors of 60?
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- Our first divisor is 2.
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2 goes into 60, leaving 30.
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- 2 goes into 30, leaving 15.
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- 2 doesn't go cleanly into 15.
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So let's move on to our next divisor, 3.
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- 3 goes cleanly into 15, leaving 5.
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- 3 does not go cleanly into 5.
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The next possible factor is 4.
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- 4 does not go cleanly into 5.
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The next possible factor is 5.
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- 5 does go cleanly into 5.
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- We're left only with 1, so now, we're done.
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Our successful divisors in that computation represent the list of prime factors of 60: 2, 2, 3, and 5.
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You can check this yourself:
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```text
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2 * 2 * 3 * 5
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= 4 * 15
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= 60
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```
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Success!

‎exercises/practice/prime-factors/.meta/config.json‎

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{
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"authors": [
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"keiravillekode"
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],
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"files": {
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"solution": [
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"PrimeFactors.pas"
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],
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"test": [
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"TestCases.pas"
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],
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"example": [
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".meta/example.pas"
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]
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},
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"blurb": "Compute the prime factors of a given natural number.",
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"source": "The Prime Factors Kata by Uncle Bob",
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"source_url": "https://web.archive.org/web/20221026171801/http://butunclebob.com/ArticleS.UncleBob.ThePrimeFactorsKata"
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}

‎exercises/practice/prime-factors/.meta/example.pas‎

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unit PrimeFactors;
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{$mode ObjFPC}{$H+}
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interface
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type
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TIntArray = Array Of Integer;
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function factors(
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const value : integer
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) : TIntArray;
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implementation
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uses SysUtils;
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function factors(
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const value : integer
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) : TIntArray;
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var
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n : integer;
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p : integer = 2;
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begin
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result := [];
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n := value;
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while n > 1 do
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if n mod p <> 0 then
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p := p + 1
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else
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begin
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insert(p, result, length(result));
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n := n div p;
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end;
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end;
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end.

‎exercises/practice/prime-factors/.meta/tests.toml‎

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# This is an auto-generated file.
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#
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# Regenerating this file via `configlet sync` will:
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# - Recreate every `description` key/value pair
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# - Recreate every `reimplements` key/value pair, where they exist in problem-specifications
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# - Remove any `include = true` key/value pair (an omitted `include` key implies inclusion)
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# - Preserve any other key/value pair
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#
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# As user-added comments (using the # character) will be removed when this file
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# is regenerated, comments can be added via a `comment` key.
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[924fc966-a8f5-4288-82f2-6b9224819ccd]
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description = "no factors"
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[17e30670-b105-4305-af53-ddde182cb6ad]
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description = "prime number"
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[238d57c8-4c12-42ef-af34-ae4929f94789]
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description = "another prime number"
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[f59b8350-a180-495a-8fb1-1712fbee1158]
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description = "square of a prime"
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[756949d3-3158-4e3d-91f2-c4f9f043ee70]
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description = "product of first prime"
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[bc8c113f-9580-4516-8669-c5fc29512ceb]
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description = "cube of a prime"
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[7d6a3300-a4cb-4065-bd33-0ced1de6cb44]
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description = "product of second prime"
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[073ac0b2-c915-4362-929d-fc45f7b9a9e4]
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description = "product of third prime"
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[6e0e4912-7fb6-47f3-a9ad-dbcd79340c75]
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description = "product of first and second prime"
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[00485cd3-a3fe-4fbe-a64a-a4308fc1f870]
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description = "product of primes and non-primes"
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[02251d54-3ca1-4a9b-85e1-b38f4b0ccb91]
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description = "product of primes"
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[070cf8dc-e202-4285-aa37-8d775c9cd473]
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description = "factors include a large prime"
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include = false

‎exercises/practice/prime-factors/Makefile‎

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SHELL = /bin/bash
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MAKEFLAGS += --no-print-directory
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DESTDIR = build
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EXECUTABLE = $(DESTDIR)/test
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COMMAND = fpc -l- -v0 -g -gl -Sa -Cr -Sehnw -Fu./lib test.pas -FE"./$(DESTDIR)"
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.ONESHELL:
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test:
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@mkdir -p "./$(DESTDIR)"
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@cp -r ./lib "./$(DESTDIR)"
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@$(COMMAND) && ./$(EXECUTABLE) $(test)
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clean:
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@rm -fr "./$(DESTDIR)"

‎exercises/practice/prime-factors/PrimeFactors.pas‎

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unit PrimeFactors;
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{$mode ObjFPC}{$H+}
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interface
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type
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TIntArray = Array Of Integer;
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function factors(
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const value : integer
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) : TIntArray;
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implementation
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uses SysUtils;
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function factors(
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const value : integer
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) : TIntArray;
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begin
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raise ENotImplemented.Create('Please implement your solution.'); result := [value];
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end;
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end.

‎exercises/practice/prime-factors/TestCases.pas‎

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unit TestCases;
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{$mode ObjFPC}{$H+}
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interface
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uses Classes, SysUtils, FPCUnit, TestRegistry, FPCUnitTestUtils;
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type
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PrimeFactorsTest = class(TTestCase)
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published
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procedure no_factors;
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procedure prime_number;
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procedure another_prime_number;
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procedure square_of_a_prime;
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procedure product_of_first_prime;
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procedure cube_of_a_prime;
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procedure product_of_second_prime;
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procedure product_of_third_prime;
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procedure product_of_first_and_second_prime;
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procedure product_of_primes_and_non_primes;
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procedure product_of_primes;
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end;
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implementation
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uses PrimeFactors;
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// 924fc966-a8f5-4288-82f2-6b9224819ccd
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procedure PrimeFactorsTest.no_factors;
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var
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expect : TIntArray;
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actual : TIntArray;
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begin
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expect := [];
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actual := PrimeFactors.factors(1);
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TapAssertTrue(Self, 'no factors', expect, actual);
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end;
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// 17e30670-b105-4305-af53-ddde182cb6ad
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procedure PrimeFactorsTest.prime_number;
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var
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expect : TIntArray;
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actual : TIntArray;
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begin
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expect := [2];
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actual := PrimeFactors.factors(2);
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TapAssertTrue(Self, 'prime number', expect, actual);
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end;
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// 238d57c8-4c12-42ef-af34-ae4929f94789
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procedure PrimeFactorsTest.another_prime_number;
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var
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expect : TIntArray;
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actual : TIntArray;
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begin
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expect := [3];
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actual := PrimeFactors.factors(3);
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TapAssertTrue(Self, 'another prime number', expect, actual);
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end;
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// f59b8350-a180-495a-8fb1-1712fbee1158
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procedure PrimeFactorsTest.square_of_a_prime;
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var
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expect : TIntArray;
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actual : TIntArray;
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begin
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expect := [3, 3];
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actual := PrimeFactors.factors(9);
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TapAssertTrue(Self, 'square of a prime', expect, actual);
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end;
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// 756949d3-3158-4e3d-91f2-c4f9f043ee70
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procedure PrimeFactorsTest.product_of_first_prime;
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var
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expect : TIntArray;
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actual : TIntArray;
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begin
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expect := [2, 2];
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actual := PrimeFactors.factors(4);
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TapAssertTrue(Self, 'product of first prime', expect, actual);
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end;
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// bc8c113f-9580-4516-8669-c5fc29512ceb
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procedure PrimeFactorsTest.cube_of_a_prime;
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var
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expect : TIntArray;
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actual : TIntArray;
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begin
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expect := [2, 2, 2];
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actual := PrimeFactors.factors(8);
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TapAssertTrue(Self, 'cube of a prime', expect, actual);
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end;
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// 7d6a3300-a4cb-4065-bd33-0ced1de6cb44
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procedure PrimeFactorsTest.product_of_second_prime;
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var
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expect : TIntArray;
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actual : TIntArray;
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begin
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expect := [3, 3, 3];
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actual := PrimeFactors.factors(27);
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TapAssertTrue(Self, 'product of second prime', expect, actual);
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end;
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// 073ac0b2-c915-4362-929d-fc45f7b9a9e4
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procedure PrimeFactorsTest.product_of_third_prime;
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var
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expect : TIntArray;
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actual : TIntArray;
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begin
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expect := [5, 5, 5, 5];
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actual := PrimeFactors.factors(625);
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TapAssertTrue(Self, 'product of third prime', expect, actual);
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end;
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// 6e0e4912-7fb6-47f3-a9ad-dbcd79340c75
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procedure PrimeFactorsTest.product_of_first_and_second_prime;
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var
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expect : TIntArray;
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actual : TIntArray;
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begin
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expect := [2, 3];
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actual := PrimeFactors.factors(6);
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TapAssertTrue(Self, 'product of first and second prime', expect, actual);
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end;
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// 00485cd3-a3fe-4fbe-a64a-a4308fc1f870
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procedure PrimeFactorsTest.product_of_primes_and_non_primes;
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var
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expect : TIntArray;
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actual : TIntArray;
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begin
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expect := [2, 2, 3];
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actual := PrimeFactors.factors(12);
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TapAssertTrue(Self, 'product of primes and non-primes', expect, actual);
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end;
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// 02251d54-3ca1-4a9b-85e1-b38f4b0ccb91
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procedure PrimeFactorsTest.product_of_primes;
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var
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expect : TIntArray;
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actual : TIntArray;
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begin
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expect := [5, 17, 23, 461];
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actual := PrimeFactors.factors(901255);
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TapAssertTrue(Self, 'product of primes', expect, actual);
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end;
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initialization
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RegisterTest(PrimeFactorsTest);
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end.

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