Deduplicate - factorial

[hobovsky]

From wiki list

1. Recursion #1 - Factorial

• 7 kyu
• Recursion is enforced (reportedly in a bad way)
• Satisfaction 88% with 8k+ completions
• 4 pending issues
• 5 languages + 1 pending translation
• Published Jan 2016, author inactive

2. Factorial

• 7 kyu
• error should be raised on out-of-range inputs
• Satisfaction 88% with ~35k completions
• 2 pending issues
• 7 languages + 2 pending translations
• Published Mar 2015, author last active Feb 2023

3. Factorial

• 7 kyu
• Satisfaction 91% with ~20k completions
• 1 pending issue
• 19 languages + 6 pending translations
• Published Aug 2016, author inactive

4. Factorial Factory

• 7 kyu
• Negative inputs expect null
• Satisfaction 88% with 8.6k completions
• 1 pending issue
• 5 languages + 1 pending translation
• Published Nov 2013, author inactive

5. Big Factorial

• 7 kyu
• Inputs are large and result in large results
• Satisfaction 90% with 2k completions
• No pending issues
• 3 languages + 2 pending translations
• Published Feb 2015, author inactive

6. Reverse Factorials

• 7 kyu
• Reverse of a factorial function: is it still a duplicate?
• Satisfaction 91% with 1k completions
• 3 pending issues
• 5 languages, no pending translations
• Published Oct 2016, author inactive

7. The Non-Discriminate Factorial

• 6 kyu
• Extends domain into negative numbers
• Satisfaction 88% with 903 completions
• No pending issues
• 5 languages + 3 pending translations
• Published Aug 2014, author inactive

---

Partial conclusion:

• Keep 3. Factorial
• Keep 6. Reverse Factorials
• Retire 1. Recursion #1 - Factorial
• Retire 4. Factorial Factory
• Retire 5. Big Factorial

I will try to get some more votes for kata 2. and 7. and see what users want to do with them.

[hobovsky]

I have no good idea how to pick a candidate to keep:

• I think kata 1. can go, because restricting solutions to only recursive ones can be problematic in many ways.
• Kata 2. has potentially interesting aspect of error handling
• Kata 3. is most complete
• Kata 4. is the oldest
• Kata 5. focuses on big integers, and IMO would be one of candidates to keep
• The task of kata 6. is slightly different than "just factorial"
• Kata 7. is also slightly different, but I do not know if sufficiently to be kept.

I think kata 5. and 6. can stay as sufficiently different to be kept, especially in languages where bigint types are not the default integer types.
I don;t like code restrictions in general, so I'd vote kata 1. to retire.
From kata 2., 3., and 4. I have no good candidates to keep, but I think one of them should be enough. Maybe 3. as most complete?
I have no opinion on kata 7., I do not know what to do with it.

[monadius]

I vote to keep 3 and 6 only. 6 should be updates to handle large factorials.

I personally don't thinks that large factorials (5) add anything new to this task: There are already many iterative factorial implementations in 3.

7 is a borderline kata. It may stay. But it seems to be overranked and its factorial definition for negative numbers is easy to implement.

[EloiseRosen]

I like 7! Vote to keep 3, 6, and 7 and retire the others.

[armeanco]

My vote:
3. Factorial
6. Reverse Factorials

[CiprianAmza]

Remove 1, 4, 5 as not having enough translations and 7 as being overranked
Keep 2 (error handling seems interesting)
Keep 3 (lots of translations)
Keep 6 (a different way of handling recursive cases)

[hobovsky]

No one voted to keep 1., 4., or 5., so I think these are good to go.
Kata 3. and 6. are unanimously voted to stay.

I am yet not sure what to do with 2. and 7., let's see if there are any other votes for these two.

[4500zenja1]

I guess 2. may be applicable for those langauges where large numbers aren't supported (not those ones which may have reaaaally big numbers like JS or Python), for C/C++/Java without specialized imports, maybe?

I guess it may stay here, as well as 6. – factorials for negatives are pretty interesting lol. (I wonder if anybody thought about factorials with float arguments – like, 3.14! = 3! + 0.14 * (4! - 3!) = 8.52 or smth like that)