Conference hydra::amiga_v1

    RE: < Note 1897.0 by RAVEN1::EVERHART >
       -< Need help with sorting program. >-


#include <stdio.h>
#include <math.h>
#include <ctype.h>
#define nswap(x,y) (temp=(x), (x)=(y), (y)=temp)

extern void Zheapsort (int [],int)   <<<<<<<<<< try this, it should compile!
                                                Regards, Som Tenna
    
main()
{
int a[10], n=0;
while (n<10) scanf("%d",&a[n++]);
Zheapsort (a,9);
n=0;
while (n<10) printf("%d",a[n++]);
}

static void adjust(v,m,n)
int v[], m;
register int n;
{
   register int *b, j, k, temp;
   b=v-1;
   j=m;
   k=m*2;
   while (k<=n)
      {
         if((k<n) && (b[k]<b[k+1])) ++k;
         if (b[j] <b[k]) nswap (b[j], b[k]);
         j=k;
         k=k*2;
      }
}

void Zheapsort (v1,n)

int v1[], n;
    

{
   int *b, j, temp;
   b=v1-1;
   for (j=n/2; j>0; j--) adjust(v1,j,n);
   for (j=n-1; j>0;j--) { nswap (b[1], b[j+1]); adjust (v1,1,j); }
}

      

    
    

    Its obviously a dual problem:
    
    	fatal lack of comments
    	terminal use of meaningless variables

    Just to add a little information to the fix in .1 ...
    
    The first time the C compiler sees a particular function (whether
    it be a declaration a definition or an invocation) it determines
    the return type of that function. Type int is the default return
    type of a function if none is specified. With these facts in mind...
    	The first time the compiler sees Zheapsort() is in the invocation
    	in main() "Zheapsort(a,9);". At this point the compiler determines
    	(by default) that the return type of Zheapsort() is int.
    
    	The next time the compiler sees Zheapsort() is in the definition
    	"void Zheapsort(v1,n)" where you "redefine" it's return type
    	to void.
    
    So (as stated in .1) anytime you call a function before you define
    it (or it's defined in another module/file) AND it returns something
    other than type int THEN you must declare it (and it's return type)
    before the place in the program where it is first called.
    
    	Ray

    OK.  I see what happened now.  Actually, I didn't write this, so
    don't flame me for not putting in comments.  A friend of mine typed
    it in from a book exactly as you see it, but it didn't work.  Maybe
    I should put the name of the book in here so the authors can be
    flamed for such a lousy example program?
    
    I was just too tired to find the problem.
    
     - Chris
    

      >> I was just too tired to find the problem.
    Do we get a percentage of your commision?
    
    	Ray

    re .5
    
    Sure.  I'll give you 80% of my commision for this little program.
    Let's see: .80 x 0 = $0.00 - Taxes = $4530.00
    
    Gee, I guess you owe Uncle Sam $4530.00.  Sounds about right for
    our tax system.
    
    :-)
    
     - Chris
    
    * P.S.  I have no money to spread around.
    :-)