code is duplicated in stack.c

NN/stack.cc

-	static struct node
-	{ int key; struct node *next; };
-	static struct node *head, *z, *t;
-	stackinit() 
-	   {
-	     head = (struct node *) malloc(sizeof *head);
-	     z = (struct node *) malloc(sizeof *z);
-	     head->next = z; head->key=0;
-	     z->next = z;
-	     z->key = 0;
-	   }
-	push(p)
-           int *p;
-	   {
-	     int v;
-	     v = *p;
-	     t = (struct node *) malloc(sizeof *t);	
-	     t->key = v; t->next = head->next;	
-	     head->next =t;	
-	   }
-	pop(x)
-           int *x;
-	   {
-	     t = head->next; head->next = t->next;
-	     *x = t->key;
-	     free(t);
-	   }
-	stackempty(i)
-          int *i;
-	  { 
-	    *i = 0;
-            if(head->next == z) *i = 1;
-          }
-        stackflush()
-           {
-             free(head);
-             free(z);
-           }