home *** CD-ROM | disk | FTP | other *** search
- Newsgroups: comp.lang.c++
- Path: in2.uu.net!allegra!alice!ark
- From: ark@research.att.com (Andrew Koenig)
- Subject: Re: Can I do it recursively?
- Message-ID: <DpDDs4.3ut@research.att.com>
- Organization: AT&T Research, Murray Hill NJ
- References: <4juo6m$n6i@doc.zippo.com>
- Date: Fri, 5 Apr 1996 03:31:15 GMT
-
- In article <4juo6m$n6i@doc.zippo.com> Clarence Chiang writes:
-
- > I don't think it is a question of whether the problem can be solved recursively
- > or iteratively. It is just that this problem is one of those NP-complete problem,
- > which requires exponential amount of time as the problem size grows.
-
- I wrote a program to do an 8x8 knight's tour somewhere around 1977.
- At the time it took about three minutes of cpu time on an IBM 360/91.
- That was a pretty big mainframe -- at one time it was the fastest
- general-purpose computer availble in the world.
-
- By today's standards, it was about as fast as a cheap PC:
- its basic clock rate was only 16 MHz but it was capable of
- executing one complete instruction per clock cycle under good
- conditions. Under typical conditions, it did about 5-10 MIPS.
-
- So I would expect a solution to the problem today to run in
- a couple of minutes. Not a big deal.
- --
- --Andrew Koenig
- ark@research.att.com
-