#include "c:stack.h"
 
/* initializes stack by setting top to 0 */
void CreateStack(STACK_TYPE *stack)
{ stack->top=0;
}
 
/* resets stack by resetting top to 0 */
void DestroyStack(STACK_TYPE *stack)
{  stack->top=0;
}
 
/* checks if stack is empty (if top is 0) */
BOOLEAN EmptyStack(STACK_TYPE *stack)
{ if (stack->top==0)
     return TRUE;
  else
     return FALSE;
}
         
/* checks if stack is full (if top is MAX_STACK) */
BOOLEAN FullStack(STACK_TYPE *stack)
{ if (stack->top == MAX)
     return TRUE;
  else
     return FALSE;
}
 
/* put item at position top and then increment top */
void Push(STACK_TYPE *stack, ITEM_TYPE newitem)
{  stack->item[stack->top]=newitem;
   stack->top++;
}
 /* decrement top by 1 and then copy the item at top */
void Pop(STACK_TYPE *stack, ITEM_TYPE *old_item)
{   stack->top--;
    *old_item=stack->item[stack->top];
}