Message-ID: <390C2854.A93F5E85@earthlink.net>
From: Martin Ambuhl <mambuhl AT earthlink DOT net>
Organization: Nocturnal Aviation
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Newsgroups: comp.os.msdos.djgpp
Subject: Re: Array swapping.
References: <390B75BB DOT 621F846A AT gtcom DOT net> <be7ngssbe6fnhur5if8j27a3ct35gpj2e9 AT 4ax DOT com>
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Date: Sun, 30 Apr 2000 12:33:27 GMT
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To: djgpp AT delorie DOT com
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Chris Mears wrote:

> Uncompiled, untested.

Obviously, since it doesn't work.  But notice this:

/* This is valid under both C99 and GNUC */
#include <stdio.h>

void swap(int m, int n, float a[m][n], float b[m][n])
{
     int i, j;
     float temp;                      /* moved to avoid possible
                                         non-optimized allocation
problems */

     for (i = 0; i < m; i++)
          for (j = 0; j < n; j++)
          {
                temp = a[i][j];
                a[i][j] = b[i][j];
                b[i][j] = temp;   /* error in CM's code fixed */
          }
}

float x[50][25] = { {1} }, y[50][25] = { { 2} };

int main(void)
{
     printf("before swap, x[0][0] = %f, y[0][0] = %f\n",
              x[0][0], y[0][0]);
     swap(50, 25, x, y);
     printf("after swap, x[0][0] = %f, y[0][0] = %f\n",
              x[0][0], y[0][0]);
     return 0;
}





> 
> void swap(float a[50][50], float b[50][50])
> {
>     int i;
>     int j;
> 
>     for (i = 0 ; i < 50 ; i++)
>     {
>         for (j = 0 ; j < 50 ; j++)
>         {
>             float temp = a[i][j];
>             a[i][j] = b[i][j];
>             b[i][j] = a[i][j];
>         }
>     }
> }
> 
> --
> Chris Mears
> 
> ICQ: 36697123

-- 
Martin Ambuhl	mambuhl AT earthlink DOT net

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know how to learn. - Henry Adams

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