Stack.java

/* Joshua Villasenor
	masc0431
 */
package data_structures;
import java.util.*;

public class Stack <E> implements Iterable<E> {
	ListADT <E> list;
	public Stack(){
		list = new LinkedListDS<E>();
	}
	// inserts the object obj into the stack
    public void push(E obj) {
    	list.addFirst(obj);
    }
    
    // pops and returns the element on the top of the stack    
    public E pop() {
    	return list.removeFirst();
    }
    
    // returns the number of elements currently in the stack
    public int size() {
    	return list.size();
    }
    
    // return true if the stack is empty, otherwise false
    public boolean isEmpty()  {
    	return list.isEmpty();
    }
    
    // returns but does not remove the element on the top of the stack    
    public E peek() {
    	return list.peekFirst();
    }
     
    // returns true if the object obj is in the stack,
    // otherwise false   
    public boolean contains(E obj) {
    	return list.contains(obj);
    }
    
    // returns the stack to an empty state    
    public void makeEmpty() {
    	list.makeEmpty();
    }
    
    // removes the Object obj if it is in the stack and
    // returns true, otherwise returns false.
    public boolean remove(E obj) {
    	return list.remove(obj);
    }
    
    // returns a iterator of the elements in the stack.  The elements
    // must be in the same sequence as pop() would return them.    
    public Iterator<E> iterator() {
    	return list.iterator();
    }

}