Timeline for Is this number a factorial?

9 events

when toggle format	what	by	license	comment
Jun 17, 2020 at 9:04	history	edited	Community Bot		Commonmark migration
May 23, 2017 at 14:01	comment	added	sudee		Check out Laikoni's answer for division based approach.
May 23, 2017 at 2:48	comment	added	Jon Purdy		Nice and simple. I thought I could do better with division—say, `divMod` by `[1..]` successively until reaching a zero remainder with a quotient of 1 (factorial) or a nonzero remainder (non-factorial), but it doesn’t seem to be the right approach. I did find this cute 46-character solution, though: `f\|let x%n=mod n x==0&&(x+1)%div n x\|\|n==1=(1%)`.
May 20, 2017 at 16:24	comment	added	sudee		I meant something along the lines of "the solution should terminate within a reasonable timeframe", but I guess it fits the requirements either way. Thanks!
May 20, 2017 at 16:20	history	edited	sudee	CC BY-SA 3.0	added 79 characters in body
May 20, 2017 at 12:44	comment	added	Laikoni		None that I am aware of. code-golf asks for a solution in as few bytes as possible without any efficiency statements. Also on my machine the function works up to `40430` without noticeable delay.
May 20, 2017 at 12:15	comment	added	sudee		Isn't there some rule about code efficiency?
May 20, 2017 at 11:17	comment	added	Laikoni		`f n=elem n$scanl1(*)[1..n]` is ridiculous inefficient but shorter.
May 20, 2017 at 10:04	history	answered	sudee	CC BY-SA 3.0