package stack;

import exceptions.EmptyStackException;


/**
 * Created with MONSTER.
 * User: xgiovio
 * Date: 05/03/14
 * Time: 0.12
 */
//Copyright (c) 2003 Brown University, Providence, RI
//Additional modifications and methods by xgiovio

public class ArrayStack<E> implements Stack<E> {


    public ArrayStack(){

        stack = (E[])new Object[dcapacity];

    }
    public ArrayStack(int size){

        stack = (E[])new Object[size];

    }


    @Override
    public void push(E element)  {
               if (stack.length == (top + 1)){
                   E[] stack2 = (E[])new Object[(stack.length *2)];
                   for (int i = 0; i<= top; i++){
                       stack2[i] = stack[i];
                   }
                   stack = stack2;
                   top++;
                   stack[top] = element;
               }else{
                   top++;
                   stack[top] = element;
               }
    }

    @Override
    public E top() throws EmptyStackException {
        if (isEmpty())
            throw new EmptyStackException();
            return stack[top];
    }

    @Override
    public E pop() throws EmptyStackException {
        if (isEmpty())
            throw  new EmptyStackException();
            top--;
            return stack[top + 1];
    }

    @Override
    public boolean isEmpty() {
        if (size() < 1)
            return true;
            return false;
    }


    @Override
    public int size() {
        return (top + 1);
    }

    @Override
    public String toString() {
        String to_return = "";
        to_return = to_return + "[";
        for (int i = 0;i<=top;i++){
            if ( i == top){
                to_return+=(stack[i].toString());
            }else{
                to_return+=(stack[i].toString() + ",");
            }
        }
        to_return = to_return + "]";

    return to_return;
    }

    private int top = -1;
    private int dcapacity = 100;
    private E[] stack;

}