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From: Michael S <already5chosen@yahoo.com>
Newsgroups: comp.lang.c
Subject: Re: Suggested method for returning a string from a C program?
Date: Sat, 22 Mar 2025 19:12:13 +0200
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On Sat, 22 Mar 2025 13:25:43 +0000
Richard Heathfield <rjh@cpax.org.uk> wrote:

> On 22/03/2025 08:07, Peter 'Shaggy' Haywood wrote:
> 
> <snip>
> 
> >    Here's my solution, for what it's worth:
> > 
> > #include <stdio.h>
> > 
> > unsigned long weird(unsigned long n)
> > {
> >    printf("%lu", n);
> > 
> >    if(n & 1)
> >    {
> >      /* Odd - multiply by 3 & add 1. */
> >      n = n * 3 + 1;  
> 
> Or you can save yourself a multiplication
> 
> n = (n << 2) - (n - 1);
> 
> potentially shaving entire picoseconds off the runtime.
> 
> >    }
> >    else
> >    {
> >      /* Even - divide by 2. */
> >      n /= 2;  
> 
> do
> {
>    n >>= 1;
> } while(~(n & 1));
> 
> ...and there goes another attosecond.
>