CS314 Fall 2002
Assignment 3

#1. Assume that our block-structured language allows the declaration
    of an array of variable size, i.e., an array which size can
    change dynamically during program execution. 

    Example:

       proc Foo (...) {
         int array a[];
         int i, n, m;

         read(n);
         for (i=0; i<n; i++) {
           a[i] = 0;
         }        

         read(m);
         for (i=0; i<m; i++) {
           a[i] = a[i] + 1;
         }        
       }

    Discuss based on an example what the problems are, if the
    array is allocated
	(i)in the static area, or
        (ii) on the stack, i.e., within the stack frame of procedure foo, or
        (iii) on the heap.
   `
#2  Given the following correct program in C, 
  (a) fill in the blanks to make the types correct in the statements shown. 
  (b) show the output from this program. 
  (c) write a statement involving a pointer expression using the
      variables in this program which is ILLEGAL given your declared types. 


main() { int a, b, c;
        _________ra,___________rb,_________rc;
        _________rra,__________rrb,________rrc;

        a = 1; b= 2; c = 3;
        ra = &a; 
        rb = &b; 
        rc = &c;
        ra = rb; 
        rra = &rb;
        rc = *rra; 
        rrc = rra;
        rc = &a;
        rrb = &rc;
        rb = &c;    
        *ra = 4;
        *rb = *ra + 5; 
        
printf ("%d %d %d\n",a,b,c);
printf("%d %d\n",*ra,*rb);
printf("%d %d %d\n",**rra,**rrb,**rrc);
}