#include "mydefs2b.h"
#include <assert.h>
// Linked list implementation of stacks.

node :: node(int d, node* n)
{
	data = d;
	next = n;
}
int Istack :: pop()
{
	assert( !isempty() );
	int temp = top -> data;		// get data
	node* oldtop = top;		// point to old
	top = top -> next;			// unlink old
	delete oldtop;				// discard
	return temp;
}