{
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        {
            "cell_type": "markdown",
            "metadata": {},
            "source": ["# Prime Factors\n", "\n", "Compute the prime factors of a given natural number.\n", "\n", "A prime number is only evenly divisible by itself and 1.\n", "\n", "Note that 1 is not a prime number.\n", "\n", "## Example\n", "\n", "What are the prime factors of 60?\n", "\n", "- Our first divisor is 2. 2 goes into 60, leaving 30.\n", "- 2 goes into 30, leaving 15.\n", "  - 2 doesn't go cleanly into 15. So let's move on to our next divisor, 3.\n", "- 3 goes cleanly into 15, leaving 5.\n", "  - 3 does not go cleanly into 5. The next possible factor is 4.\n", "  - 4 does not go cleanly into 5. The next possible factor is 5.\n", "- 5 does go cleanly into 5.\n", "- We're left only with 1, so now, we're done.\n", "\n", "Our successful divisors in that computation represent the list of prime\n", "factors of 60: 2, 2, 3, and 5.\n", "\n", "You can check this yourself:\n", "\n", "- 2 * 2 * 3 * 5\n", "- = 4 * 15\n", "- = 60\n", "- Success!\n", "\n", "## Source\n", "\n", "The Prime Factors Kata by Uncle Bob [http://butunclebob.com/ArticleS.UncleBob.ThePrimeFactorsKata](http://butunclebob.com/ArticleS.UncleBob.ThePrimeFactorsKata)\n", "\n", "## Version compatibility\n", "This exercise has been tested on Julia versions >=1.0.\n", "\n", "## Submitting Incomplete Solutions\n", "It's possible to submit an incomplete solution so you can see how others have completed the exercise."]
        },
        {
            "cell_type": "markdown",
            "metadata": {},
            "source": ["## Your solution"]
        },
        {
            "cell_type": "code",
            "execution_count": null,
            "metadata": {},
            "outputs": [],
            "source": ["# submit\n", ""]
        },
        {
            "cell_type": "markdown",
            "metadata": {},
            "source": ["## Test suite"]
        },
        {
            "cell_type": "code",
            "execution_count": null,
            "metadata": {},
            "outputs": [],
            "source": ["# include(\"prime-factors.jl\")\n", "using Test\n", "\n", "@testset \"no factors\" begin\n", "    @test prime_factors(1) == []\n", "end\n", "\n", "@testset \"prime number\" begin\n", "    @test prime_factors(2) == [2]\n", "end\n", "\n", "@testset \"square of a prime\" begin\n", "    @test prime_factors(9) == [3, 3]\n", "end\n", "\n", "@testset \"cube of a prime\" begin\n", "    @test prime_factors(8) == [2, 2, 2]\n", "end\n", "\n", "@testset \"product of primes and non-primes\" begin\n", "    @test prime_factors(12) == [2, 2, 3]\n", "end\n", "\n", "@testset \"product of primes\" begin\n", "    @test prime_factors(901255) == [5, 17, 23, 461]\n", "end\n", "\n", "@testset \"factors include a large prime\" begin\n", "    @test prime_factors(93819012551) == [11, 9539, 894119]\n", "end"]
        },
        {
            "cell_type": "markdown",
            "metadata": {},
            "source": [
                "## Prepare submission\n",
                "To submit your exercise, you need to save your solution in a file called `prime-factors.jl` before using the CLI.\n",
                "You can either create it manually or use the following functions, which will automatically write every notebook cell that starts with `# submit` to the file `prime-factors.jl`.\n"
            ]
        },
        {
            "cell_type": "code",
            "execution_count": null,
            "metadata": {},
            "outputs": [],
            "source": [
                "# using Pkg; Pkg.add(\"Exercism\")\n",
                "# using Exercism\n",
                "# Exercism.create_submission(\"prime-factors\")"
            ]
        }
    ],
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