/**
 * This is a simple stack implementation, using an array
 * of fixed size.  Only a stack of int is considered.
 * It has been modified to throw exceptions and to implement the
 * Stack interface.
 */

/**
 * @author Melvin Fitting
 * @version March 5, 2008
 *
 */
public class ArrayStack implements Stack {
	private static final int MAX_SIZE = 100;
	private int[] numbers = new int[MAX_SIZE];
	private int count = 0;
	
	public boolean isEmpty(){
		return count == 0;
	}
	
	public int peek(){
		if (count==0) throw new StackException("Stack underflow in peek");
		return numbers[count-1];
	}
	
	public void push(int n){
		if (count==numbers.length) throw new StackException("Stack overflow in push");
		numbers[count] = n;
		count++;
		//numbers[count++] = n;
	}
	
	public int pop(){
		if (count==0) throw new StackException("Stack underflow in pop");
		count--;
		return numbers[count];
		//return numbers[--count];
	}
}