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From: Tim Rentsch <tr.17687@z991.linuxsc.com>
Newsgroups: comp.programming
Subject: Re: A little puzzle.
Date: Mon, 28 Nov 2022 07:30:11 -0800
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Richard Harnden <richard.nospam@gmail.com> writes:

> On 21/11/2022 20:45, 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.
>
> I think this works ...
>
> int in_subrange(int range, int start, int end, int check)
> {
>     check %= range;
>
>     if (  ( end < start && (
>                (check >= 0 && check <= end)
>             || (check >= start && check < range)
>             )
>           )
>        || ( check >= start && check <= end )
>        )
>             return 1;
>
>     return 0;
> }

Have you thought about a case where the values of check, start,
and end are chosen from the interval -9000000000 to 9000000000?
How about the interval -18000000000 to 18000000000?