#include "stack.h"
#include <iostream>


StackT::StackT(){
    size = 10;
    data = new ItemT[size];
    top = 0;

    return;
}

// supply the three missing routines.

void StackT::Push(ItemT i) {
     if (top < size) {
         data[top] = i;
	 top++;
     } else {
         // supply the missing code.
     }

     return;
}

ItemT StackT::Pop(void){
   ItemT rv;
   if (top > 0) {
       top--;
       rv = data[top];

       // add a code to reduce the stack size if top < 1/3 size
   }
   return rv;
}

ItemT StackT::Top(void) const{
   ItemT rv;
   if (top > 0) {
       rv =  data[top-1];
   }
   return rv;
}

int StackT::Size(void) const{
    return top;
}

bool StackT::IsEmpty(void) const{
    return top==0;
}