Prime Factors

Challenge Overview

Compute the prime factors of a given natural number.

Visit the prime-factors exercise on Exercism to read the full instructions and download the exercise files.

Community Solutions

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The following are the top 3 community solutions by stars:

Solution 1 by @fifiman (⭐ 0) — View on Exercism
Solution 2 by @glennj (⭐ 0) — View on Exercism
Solution 3 by @nzok (⭐ 0) — View on Exercism

Source: Exercism sml/prime-factors

💡 View Solution

fun primeFactors n =
  let fun getPrimeFactors num curDivider = 
    if curDivider * curDivider > num then
        if num > 1 then [num] else []
    else if num mod curDivider = 0 then [curDivider] @ getPrimeFactors (num div curDivider) curDivider
    else getPrimeFactors num (curDivider + 1)
  in
    getPrimeFactors n 2
  end