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.
What are the prime factors of 60?
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!
Simply type make chez
if you're using ChezScheme or make guile
if you're using GNU Guile.
Sometimes the name for the scheme binary on your system will differ from the defaults.
When this is the case, you'll need to tell make by running make chez chez=your-chez-binary
or make guile guile=your-guile-binary
.
(load "test.scm")
at the repl prompt.prime-factors.scm
reloading as you go.(test)
to check your solution.If some of the test cases fail, you should see the failing input and the expected output.
The failing input is presented as a list because the tests call your solution by (apply prime-factors input-list)
.
To learn more about apply
see The Scheme Programming Language -- Chapter 5
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