Tracks
/
C
C
/
Exercises
/
Prime Factors
Prime Factors

Prime Factors

Medium

Instructions

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!

Edit via GitHub The link opens in a new window or tab
C Exercism

Ready to start Prime Factors?

Sign up to Exercism to learn and master C with 82 exercises, and real human mentoring, all for free.