usr/lib/learn/C/L32.1a

#print
Write a program
   pair(a,b)
which accepts as arguments two pointers to integers
and swaps the integers if necessary so that the
first argument points to the larger one; that is
        int x,y;
        x = 9;
        y = 15;
        pair( &x, &y);
results in x being 15 and y 9.  Leave the program
on file "pair.c"; compile, test it, and type "ready".
#once #create tzaqc.c
main()
{
int x,y;
y=200;
x = 0;
pair(&y, &x);
if (x!=0 || y !=200) return(1);
pair(&x,&y);
if (x!=200 || y !=0) return(1);
x = 30;
y = 23097;
pair(&x,&y);
if (x!= 23097 || y!= 30) return(1);
return(0);
}
#user
cc tzaqc.c pair.o
a.out
#succeed
pair(a, b)
int *a, *b;
{
        int t;

        if (*a <= *b) {
                t = *a;
                *a = *b;
                *b = t;
        }
}
#log
#next
33.1a 10