Path: csiph.com!eternal-september.org!reader01.eternal-september.org!.POSTED!not-for-mail From: Ben Bacarisse Newsgroups: comp.programming Subject: Re: A little puzzle. Date: Mon, 21 Nov 2022 21:21:07 +0000 Organization: A noiseless patient Spider Lines: 36 Message-ID: <87tu2sm2bg.fsf@bsb.me.uk> References: <875yf8nijb.fsf@bsb.me.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Injection-Info: reader01.eternal-september.org; posting-host="0b7422340e19e32d781009d919f3c74c"; logging-data="4080626"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX19mvhEbisC1FH1GgIcOt+EWlx/nhTwWcbY=" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) Cancel-Lock: sha1:4j8ZRj4NeB40NmXvl1yEbgHQORs= sha1:gEBdaqQn08ITOjYHqNSj8U/Ky7c= X-BSB-Auth: 1.c11dc4831e48c83769e6.20221121212107GMT.87tu2sm2bg.fsf@bsb.me.uk Xref: csiph.com comp.programming:15919 David Brown writes: > On 21/11/2022 21:45, Ben Bacarisse wrote: >> I wonder if there are any real posters here? Let's see... >> I came across a trivial programming task that must have been solved a >> thousand times by other programmers, but it had never crossed my path >> until yesterday. I must be feeling my age because I made a real hash of >> tackling it at first. Anyway, I thought it might be of interest. >> Consider any ordered measure that "wraps round" -- bearings in degrees, >> minutes in the hour, indeed hours in either the 12 or 24 hour clock. >> The problem is to determine if a given value is in the sub-range >> specified by a start and an en value. >> I was specifically concerned with integer values where the sub-range >> includes the start value but excludes the end value. >> Though I am not sure this merits the term "puzzle", I suggest that >> solutions be posted with some spoiler protection. Do all the news >> readers used by programmers (or ex programmers) all respect the presence >> of a form-feed character... >> >> ... like this? Because that's my favourite way, rather than posting >> lots of dummy lines before the solution. >> > > Are there any restrictions, such as sticking to integers? The problem > becomes quite difficult if your measure is the reals in [0, 1) and > your "n" is, say, π/4... I don't follow. What is "my" n? I did not mention an n. I don't see why the problem can't be naturally extended to a circular real interval [0, 1), subject to the fact that we'll use floating point numbers for practical purposes. But I don't think this is what you were talking about. -- Ben.