Some solutions for the julia path

julia/difference-of-squares/.exercism/config.json

@@ -0,0 +1,23 @@
+{
+  "authors": [
+    "SaschaMann"
+  ],
+  "contributors": [
+    "bovine3dom",
+    "cmcaine"
+  ],
+  "files": {
+    "solution": [
+      "difference-of-squares.jl"
+    ],
+    "test": [
+      "runtests.jl"
+    ],
+    "example": [
+      ".meta/example.jl"
+    ]
+  },
+  "blurb": "Find the difference between the square of the sum and the sum of the squares of the first N natural numbers.",
+  "source": "Problem 6 at Project Euler",
+  "source_url": "https://projecteuler.net/problem=6"
+}

julia/difference-of-squares/.exercism/metadata.json

@@ -0,0 +1 @@
+{"track":"julia","exercise":"difference-of-squares","id":"43726f141cb245cbb9d9c8b9cbdc4dc7","url":"https://exercism.org/tracks/julia/exercises/difference-of-squares","handle":"Kimawari","is_requester":true,"auto_approve":false}

julia/difference-of-squares/HELP.md

@@ -0,0 +1,34 @@
+# 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 difference-of-squares.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/difference-of-squares/README.md

@@ -0,0 +1,34 @@
+# Difference of Squares
+
+Welcome to Difference of Squares on Exercism's Julia Track.
+If you need help running the tests or submitting your code, check out `HELP.md`.
+
+## Instructions
+
+Find the difference between the square of the sum and the sum of the squares of the first N natural numbers.
+
+The square of the sum of the first ten natural numbers is
+(1 + 2 + ... + 10)² = 55² = 3025.
+
+The sum of the squares of the first ten natural numbers is
+1² + 2² + ... + 10² = 385.
+
+Hence the difference between the square of the sum of the first ten natural numbers and the sum of the squares of the first ten natural numbers is 3025 - 385 = 2640.
+
+You are not expected to discover an efficient solution to this yourself from first principles; research is allowed, indeed, encouraged.
+Finding the best algorithm for the problem is a key skill in software engineering.
+
+## Source
+
+### Created by
+
+- @SaschaMann
+
+### Contributed to by
+
+- @bovine3dom
+- @cmcaine
+
+### Based on
+
+Problem 6 at Project Euler - https://projecteuler.net/problem=6

julia/difference-of-squares/difference-of-squares.jl

@@ -0,0 +1,14 @@
+"Square the sum of the first `n` positive integers"
+function square_of_sum(n)
+    return sum(1:n)^2
+end
+
+"Sum the squares of the first `n` positive integers"
+function sum_of_squares(n)
+    return sum((1:n).^2)
+end
+
+"Subtract the sum of squares from square of the sum of the first `n` positive ints"
+function difference(n)
+    return square_of_sum(n) - sum_of_squares(n)
+end

julia/difference-of-squares/runtests.jl

@@ -0,0 +1,27 @@
+using Test
+
+include("difference-of-squares.jl")
+
+@testset verbose = true "tests" begin
+    @testset "Square the sum of the numbers up to the given number" begin
+        @test square_of_sum(1)::Integer == 1
+        @test square_of_sum(5)::Integer == 225
+        @test square_of_sum(10)::Integer == 3025
+        @test square_of_sum(100)::Integer == 25502500
+    end
+
+    @testset "Sum the squares of the numbers up to the given number" begin
+        @test sum_of_squares(1)::Integer == 1
+        @test sum_of_squares(5)::Integer == 55
+        @test sum_of_squares(10)::Integer == 385
+        @test sum_of_squares(100)::Integer == 338350
+    end
+
+    @testset "Subtract sum of squares from square of sums" begin
+        @test difference(0)::Integer == 0
+        @test difference(1)::Integer == 0
+        @test difference(5)::Integer == 170
+        @test difference(10)::Integer == 2640
+        @test difference(100)::Integer == 25164150
+    end
+end