For each of these statements, draw a diagram showing what happens to the memory locations.

ITEM *p, *s, *r;
ITEM  x;


1. p = new ITEM;
2. s = p;
3. r = NULL;
4. s = &x;
5. delete p;
6. p = 0;

7. Carefully trace through the following program, using diagrams as needed, and indicate the output.

   {	
      int *a, *b, *c;
      a = new int; 
      *a = 10;
      b = a;
      c = new int;	
      *c = *a;	
      cout << setw(4) << *a << *b << *c << endl;
      *a = 23;
      cout << setw(4) << *a << *b << *c << endl;
      delete b; delete c;
   }
   

8. Draw diagrams to illustrate the situation after each statement at right is executed.

   struct node
   {
      int data;
      node*next;
   };
   
   int main ( )
   {
      node *s, *t;
      s = new node;
      s -> data = 12;
      t = new node;
      t -> next = s;
      t -> data = 23;
      s -> next = NULL;
      delete t; delete s;
      return 0;
   }
   

9. Draw a diagram and state the output of each segment of code below.
   • node *p, *s;
p = new node;
s = new node;
p -> data = 5;
s -> data = 6;
delete p;
p = s;
p ->data = 1;
cout << p ->data << " " << s ->data;
delete p;
p = NULL;

   • node *p, *s;
p = new node;
p ->data = 3;
s = new node;
s ->data = 2;
p = new node;
p ->data = s ->data;
s ->data = 0;
s ->next = NULL;
p ->next = s;
cout << p ->data << " " << s ->data;
delete p;
delete s;

10. Which of 9(a) and 9(b) leaves inaccessible node? a dangling pointer?