Data Structures: Stacks and Queues

Stacks. A stack is a collection that is based on the last-in-first-out (LIFO) policy. By tradition, we name the stack insert method push() and the stack remove operation pop(). We also include a method to test whether the stack is empty, as indicated in the following API:

Video Lectures :
Stacks and Queues
Clients

Assignment:
Implement the ArrayStackOfIntegers ADT for Integers using arrays.

Other members that you need to implement:

import java.util.Iterator;
import java.util.NoSuchElementException;

public class ArrayStackOfIntegers implements Iterable {
    private Integers[] items;  // holds the items
    private int n;             // number of items in stack
    public ArrayStackOfIntegers(int capacity) {
        items = (Integer[]) new Object[capacity];
    }

    public boolean isEmpty() {
        ----
    }

    public boolean isFull() {
        ----
    }

    public void push(Integer item) {
        ----
    }

    public Integer pop() {
        
    }

    public Iterator iterator() {
        return new ReverseArrayIterator();
    }

    // an iterator, doesn't implement remove() since it's optional
    private class ReverseArrayIterator implements Iterator {

    ----
    public void remove() 
    {}
    }
}

An example of Iterable

The files in this site are cleaned up a bit here.

Use the ArrayStackOfIntegers ADT  to work on these assignments:
ArrayStackOfIntegers ADT – Calculator
Design and implement a client to calculate the following postfix expression: 8 4 -3 * 1 5 + / *

 
ArrayStackOfIntegers ADT – Enhanced Calculator
 
StackCalculatorEnhanced