Some solutions for the julia path

julia/perfect-numbers/.exercism/config.json

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+{
+  "authors": [
+    "Akshat-mehrotra"
+  ],
+  "contributors": [
+    "cmcaine",
+    "miguelraz",
+    "SaschaMann",
+    "logankilpatrick"
+  ],
+  "files": {
+    "solution": [
+      "perfect-numbers.jl"
+    ],
+    "test": [
+      "runtests.jl"
+    ],
+    "example": [
+      ".meta/example.jl"
+    ]
+  },
+  "blurb": "Determine if a number is perfect, abundant, or deficient based on Nicomachus' (60 - 120 CE) classification scheme for positive integers.",
+  "source": "Taken from Chapter 2 of Functional Thinking by Neal Ford.",
+  "source_url": "https://www.oreilly.com/library/view/functional-thinking/9781449365509/"
+}

julia/perfect-numbers/.exercism/metadata.json

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+{"track":"julia","exercise":"perfect-numbers","id":"63be4afee8e04dce908a953310580ba6","url":"https://exercism.org/tracks/julia/exercises/perfect-numbers","handle":"Kimawari","is_requester":true,"auto_approve":false}

julia/perfect-numbers/HELP.md

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+# Help
+
+## Running the tests
+
+To run the tests, run this command from within the exercise directory:
+
+```bash
+$ julia runtests.jl
+```
+
+## Submitting your solution
+
+You can submit your solution using the `exercism submit perfect-numbers.jl` command.
+This command will upload your solution to the Exercism website and print the solution page's URL.
+
+It's possible to submit an incomplete solution which allows you to:
+
+- See how others have completed the exercise
+- Request help from a mentor
+
+## Need to get help?
+
+If you'd like help solving the exercise, check the following pages:
+
+- The [Julia track's documentation](https://exercism.org/docs/tracks/julia)
+- The [Julia track's programming category on the forum](https://forum.exercism.org/c/programming/julia)
+- [Exercism's programming category on the forum](https://forum.exercism.org/c/programming/5)
+- The [Frequently Asked Questions](https://exercism.org/docs/using/faqs)
+
+Should those resources not suffice, you could submit your (incomplete) solution to request mentoring.
+
+To get help if you're having trouble, we recommend that you submit your code and request mentoring :)
+
+If you don't want to do that for whatever reason, then you can find the wider Julia community channels [here](https://julialang.org/community/).

julia/perfect-numbers/README.md

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+# Perfect Numbers
+
+Welcome to Perfect Numbers on Exercism's Julia Track.
+If you need help running the tests or submitting your code, check out `HELP.md`.
+
+## Instructions
+
+Determine if a number is perfect, abundant, or deficient based on Nicomachus' (60 - 120 CE) classification scheme for positive integers.
+
+The Greek mathematician [Nicomachus][nicomachus] devised a classification scheme for positive integers, identifying each as belonging uniquely to the categories of [perfect](#perfect), [abundant](#abundant), or [deficient](#deficient) based on their [aliquot sum][aliquot-sum].
+The _aliquot sum_ is defined as the sum of the factors of a number not including the number itself.
+For example, the aliquot sum of `15` is `1 + 3 + 5 = 9`.
+
+## Perfect
+
+A number is perfect when it equals its aliquot sum.
+For example:
+
+- `6` is a perfect number because `1 + 2 + 3 = 6`
+- `28` is a perfect number because `1 + 2 + 4 + 7 + 14 = 28`
+
+## Abundant
+
+A number is abundant when it is less than its aliquot sum.
+For example:
+
+- `12` is an abundant number because `1 + 2 + 3 + 4 + 6 = 16`
+- `24` is an abundant number because `1 + 2 + 3 + 4 + 6 + 8 + 12 = 36`
+
+## Deficient
+
+A number is deficient when it is greater than its aliquot sum.
+For example:
+
+- `8` is a deficient number because `1 + 2 + 4 = 7`
+- Prime numbers are deficient
+
+## Task
+
+Implement a way to determine whether a given number is [perfect](#perfect).
+Depending on your language track, you may also need to implement a way to determine whether a given number is [abundant](#abundant) or [deficient](#deficient).
+
+[nicomachus]: https://en.wikipedia.org/wiki/Nicomachus
+[aliquot-sum]: https://en.wikipedia.org/wiki/Aliquot_sum
+
+## Source
+
+### Created by
+
+- @Akshat-mehrotra
+
+### Contributed to by
+
+- @cmcaine
+- @miguelraz
+- @SaschaMann
+- @logankilpatrick
+
+### Based on
+
+Taken from Chapter 2 of Functional Thinking by Neal Ford. - https://www.oreilly.com/library/view/functional-thinking/9781449365509/

julia/perfect-numbers/perfect-numbers.jl

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+function get_divisors(n)
+    n > 0 || throw(DomainError(n))
+    return sum(i for i in 1:n÷2 if iszero(n % i))
+end
+
+function isperfect(number)
+    return get_divisors(number) ≡ number
+end
+function isabundant(number)
+    return get_divisors(number) > number
+end
+function isdeficient(number)
+    return get_divisors(number) < number
+end

julia/perfect-numbers/runtests.jl

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+using Test
+
+include("perfect-numbers.jl")
+
+@testset verbose = true "tests" begin
+    @testset "Perfect numbers" begin
+
+        @testset "Smallest perfect number is classified correctly" begin
+            @test isperfect(6)
+        end
+
+        @testset "Medium perfect number is classified correctly" begin
+            @test isperfect(28)
+        end
+
+        @testset "Large perfect number is classified correctly" begin
+            @test isperfect(33550336)
+        end
+        
+        @testset "Correctly handles non-perfect numbers" begin
+            @test !isperfect(12)
+            @test !isperfect(4)
+        end
+    end
+
+    @testset "Abundant numbers" begin
+
+        @testset "Smallest abundant number is classified correctly" begin
+            @test isabundant(12)
+        end
+
+        @testset "Medium abundant number is classified correctly" begin
+            @test isabundant(30)
+        end
+
+        @testset "Large abundant number is classified correctly" begin
+            @test isabundant(33550335)
+        end
+
+        @testset "Correctly handles non-abundant numbers" begin
+            @test !isabundant(6)
+            @test !isabundant(32)
+        end
+    end
+
+    @testset "Deficient numbers" begin
+
+        @testset "Smallest prime deficient number is classified correctly" begin
+            @test isdeficient(2)
+        end
+
+        @testset "Smallest non-prime deficient number is classified correctly" begin
+            @test isdeficient(4)
+        end
+
+        @testset "Medium deficient number is classified correctly" begin
+            @test isdeficient(32)
+        end
+
+        @testset "Large deficient number is classified correctly" begin
+            @test isdeficient(33550337)
+        end
+
+        @testset "Edge case (no factors other than itself) is classified correctly" begin
+            @test isdeficient(1)
+        end
+
+        @testset "Correctly handles non-deficient numbers" begin
+            @test !isdeficient(28)
+            @test !isdeficient(30)
+        end
+    end
+
+    @testset "Invalid inputs" begin
+
+        @testset "Zero is rejected (not a natural number)" begin
+            @test_throws DomainError isdeficient(0)
+            @test_throws DomainError isperfect(0)
+            @test_throws DomainError isabundant(0)
+        end
+
+        @testset "Negative integer is rejected (not a natural number)" begin
+            @test_throws DomainError isdeficient(-1)
+            @test_throws DomainError isperfect(-1)
+            @test_throws DomainError isabundant(-1)
+        end
+    end
+end