Rust - Prime Factors Complete

rust/prime-factors/README.md

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+# Prime Factors
+
+Compute the prime factors of a given natural number.
+
+A prime number is only evenly divisible by itself and 1.
+
+Note that 1 is not a prime number.
+
+## Example
+
+What are the prime factors of 60?
+
+- Our first divisor is 2. 2 goes into 60, leaving 30.
+- 2 goes into 30, leaving 15.
+  - 2 doesn't go cleanly into 15. So let's move on to our next divisor, 3.
+- 3 goes cleanly into 15, leaving 5.
+  - 3 does not go cleanly into 5. The next possible factor is 4.
+  - 4 does not go cleanly into 5. The next possible factor is 5.
+- 5 does go cleanly into 5.
+- We're left only with 1, so now, we're done.
+
+Our successful divisors in that computation represent the list of prime
+factors of 60: 2, 2, 3, and 5.
+
+You can check this yourself:
+
+- 2 * 2 * 3 * 5
+- = 4 * 15
+- = 60
+- Success!
+
+## Rust Installation
+
+Refer to the [exercism help page][help-page] for Rust installation and learning
+resources.
+
+## Writing the Code
+
+Execute the tests with:
+
+```bash
+$ cargo test
+```
+
+All but the first test have been ignored.  After you get the first test to
+pass, remove the ignore flag (`#[ignore]`) from the next test and get the tests
+to pass again.  The test file is located in the `tests` directory.   You can
+also remove the ignore flag from all the tests to get them to run all at once
+if you wish.
+
+Make sure to read the [Crates and Modules](https://doc.rust-lang.org/stable/book/crates-and-modules.html) chapter if you
+haven't already, it will help you with organizing your files.
+
+## Feedback, Issues, Pull Requests
+
+The [exercism/rust](https://github.com/exercism/rust) repository on GitHub is the home for all of the Rust exercises. If you have feedback about an exercise, or want to help implement new exercises, head over there and create an issue. Members of the [rust track team](https://github.com/orgs/exercism/teams/rust) are happy to help!
+
+If you want to know more about Exercism, take a look at the [contribution guide](https://github.com/exercism/docs/blob/master/contributing-to-language-tracks/README.md).
+
+[help-page]: http://exercism.io/languages/rust
+[crates-and-modules]: http://doc.rust-lang.org/stable/book/crates-and-modules.html
+
+## Source
+
+The Prime Factors Kata by Uncle Bob [http://butunclebob.com/ArticleS.UncleBob.ThePrimeFactorsKata](http://butunclebob.com/ArticleS.UncleBob.ThePrimeFactorsKata)
+
+## Submitting Incomplete Solutions
+It's possible to submit an incomplete solution so you can see how others have completed the exercise.

rust/prime-factors/src/lib.rs

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+pub fn factors(inp: u64) -> Vec<u64>{
+    let mut number = inp;
+
+    let mut factor = 2;
+
+    let mut return_vec = Vec::new();
+
+    while number != 1 {
+        while number % factor != 0 {
+            factor += 1;
+        }
+        return_vec.push(factor);
+        number /= factor;
+        factor = 2;
+    }
+
+    return return_vec
+}

rust/prime-factors/tests/prime-factors.rs

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+extern crate prime_factors;
+
+use prime_factors::factors;
+
+#[test]
+fn test_no_factors() {
+    assert_eq!(factors(1), vec![]);
+}
+
+#[test]
+fn test_prime_number() {
+    assert_eq!(factors(2), vec![2]);
+}
+
+#[test]
+fn test_square_of_a_prime() {
+    assert_eq!(factors(9), vec![3, 3]);
+}
+
+#[test]
+fn test_cube_of_a_prime() {
+    assert_eq!(factors(8), vec![2, 2, 2]);
+}
+
+#[test]
+fn test_product_of_primes_and_non_primes() {
+    assert_eq!(factors(12), vec![2, 2, 3]);
+}
+
+#[test]
+fn test_product_of_primes() {
+    assert_eq!(factors(901255), vec![5, 17, 23, 461]);
+}
+
+#[test]
+fn test_factors_include_large_prime() {
+    assert_eq!(factors(93819012551), vec![11, 9539, 894119]);
+}