Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uflorida!haven!aplcen!bink
From: bink@aplcen.apl.jhu.edu (Ubben Greg)
Newsgroups: comp.misc
Subject: Re: programming challenge (really silly)
Keywords: dc factorial
Message-ID: <881@aplcen.apl.jhu.edu>
Date: 17 Mar 89 03:44:34 GMT
References: <2102@jasper.UUCP> <93227@sun.uucp>
Reply-To: bink@aplcen.apl.jhu.edu (Greg Ubben 301-768-9780)
Distribution: na
Organization: DoD
Lines: 21

In article <93227@sun.uucp> landauer@sun.UUCP (Doug Landauer) writes:
>Anyway, I haven't seen any other postings that solve this silly
>challenge (to write a little factorial program) in as few characters as
>does this 76-character shell/dc/sed script:
>----
>dc<<Q
>[[error]pq]se`head -1`dsnd1>ed9<e[ln1-dsn*ln2<y]syln2<y[answer is ]Pp
>----
>Can anyone improve this further?

Being somewhat of a {sh,sed,dc,awk,etc} fanatic, I couldn't resist playing
with Doug's script, coming up with the following version which is only 53
characters long (if you remove the trailing newline):

?[[error]pq]sad1>ad9<a[d1-d2<a*]sad2<a[answer is ]Ppq

This is a pure dc program, so invoke it as "dc f.dc".  I mainly
eliminated the lengthy register references by using non-tail recursion.
By the way, this is my first posting.  Hi Mom!

					-- Greg Ubben