From:	mert0407 AT sable DOT ox DOT ac DOT uk (George Foot)
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: ' ^ '
Date:	17 Oct 1997 10:25:16 GMT
Organization:	Oxford University, England
Lines:	38
Message-ID:	<627eec$2ct$1@news.ox.ac.uk>
References:	<199710160103 DOT SAA04693 AT adit DOT ap DOT net>
NNTP-Posting-Host:	sable.ox.ac.uk
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

On Thu, 16 Oct 1997 01:03:02 GMT in comp.os.msdos.djgpp Nate Eldredge
(eldredge AT ap DOT net) wrote: 

: floating-point function. For integers you can do something like:
: int int_pow(int x, int y)
: {
:    int i;
:    int t = x;
:    for (i=1; i < y; i++) t *= x;
:    return t;
: }

Or better (shorter, faster, less variables, and also allows zero powers ;)):

int int_pow (int x, int y) {
 int a = 1;
 while (y--) a*=x;
 return a;
}

or faster for larger indices:

int int_pow (int x, int y) {
 int a = 1;
 if (y<0) return 0;
 while (y) {
  if (y&1) a*=x;
  x*=x;
  y>>=1;
 }
 return a;
}

hth :)

-- 
George Foot <mert0407 AT sable DOT ox DOT ac DOT uk>
Merton College, Oxford

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