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From: Tim Rentsch <tr.17687@z991.linuxsc.com>
Newsgroups: comp.lang.c
Subject: Re: Sort of trivial code challenge - may be interesting to you anyway
Date: Fri, 06 Mar 2026 18:14:04 -0800
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DFS <nospam@dfs.com> writes:

> On 3/6/2026 11:53 AM, Tim Rentsch wrote:
>
>> Lew Pitcher <lew.pitcher@digitalfreehold.ca> writes:
>>
>>> Thanks for the observations.  I look forward to seeing /your/ code :-)
>>
>> I'm eager to post it.
>
> It's time!
>
>
>> I'm still hoping DFS will at least post an attempt.
>
> You're an optimist.  You'd make a good lion tamer.
>
> "disallow if, for, while, goto, return, and to forbid functions and
> function calls except for calls to C standard library functions.  Also
> no math library."
>
> would probably take me 3 days solid to research and write
>
> I did deliver a "no fors, whiles, gotos, or returns" version.
>
> Then I bowed out.

Have you looked up setjmp()/longjmp() yet in the C standard (or
maybe do an online search)?  That could help jog your thinking,
and once you get the main idea things might fall into place
fairly quickly.

I say again that ?: is an important part of the battle here.

Feeling merciful, I am giving one more big hint.  The outline of
my program looks like this

    ...
    ... a few #include's, macros, typedef's, variable declarations
    ...

    static jmp_buf jb;

    int
    main( int argc, char *argv[] ){
        switch(  setjmp( jb )  ){
            ...
            ... (inside the switch there are several 'case' arms)
            ... (however there are no 'break' statements used)
            ...
        }
    }

Obviously some longjmp()'s are needed in the body of the switch() to
make this all work.  Good luck!