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From: Tim Rentsch <tr.17687@z991.linuxsc.com>
Newsgroups: comp.lang.c
Subject: Re: Challenge/exercise problem - signum() function
Date: Mon, 12 Aug 2024 09:57:28 -0700
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Lew Pitcher <lew.pitcher@digitalfreehold.ca> writes:

> On Mon, 12 Aug 2024 08:17:11 -0700, Tim Rentsch wrote:
>
>> Vir Campestris <vir.campestris@invalid.invalid> writes:
>>
>>> On 12/08/2024 01:43, Tim Rentsch wrote:
>>
>> [...]
>>
>>>> Also, it would be better for your understanding of C if you would
>>>> stop thinking about what is going on at the level of actual
>>>> hardware.  Doing that serves to confuse a lot more than it helps.
>>>
>>> I think I feel my ears burning!
>>
>> I'm taking that as a compliment. :)
>>
>> Also as an impetus to post a small C exercise I've been meaning
>> to put up.
>>
>> The goal is to write a C function to compute a signum() value:
>>
>>     long
>>     signum( long k ){
>>         /* should return
>>          *      -1 if k < 0
>>          *      +1 if k > 0
>>          *       0 otherwise
>>         **/
>>         /* ... */
>>         return  0; /* appropriate return value to be supplied */
>>     }
>
> [snip]
>
> Didn't we do something like this a few years ago, when someone
> complained that strcmp() did /not/ return -1, 0, or +1 on
> lessthan, equalto, or greaterthan string comparisons?

Certainly there have been similar exercises, but I don't remember
seeing this exact question.  The added restrictions make it more
difficult than it might appear.

> If I still have my "solution" around, I'll post it to followup
> the more current solutions.

Thank you, it would be good to see that.