LinkedStack

import java.util.EmptyStackException;


public class LinkedStack<T> {

    Node head;
    int count;

    public void push(T item) {
        if (head == null) {
            // The stack is empty
            Node newNode = new Node(item, null);
            head = newNode;
        } else {
            // Stack is not empty, create a new node at the top of the stack
            // The new item's next link goes to the "old" head
            Node newNode = new Node(item, head);

            // Now we can re-assign the link to the new head
            head = newNode;
        }
    }

    public T pop() throws EmptyStackException {
        // TODO: Write code to add pop functionality
        if (head == null) {
            throw new EmptyStackException();
        }
        else{
            T result = head.getData();
            head = head.getNext();
            count--;
            return result;
        }
    }

    public T peek() {
        // TODO: Write code to add peek functionality
        if (head == null) {
            throw new EmptyStackException();
        }
        else {
            return head.data;
        }
    }

    public int length() {
        Node n = head;
        int length = 0;
        while (n != null) {
            length++;
            n = n.next;
        }
        return length;
    }

    @Override
    public String toString() {
        // TODO: Write code to add toString functionality
        return "";
    }

    // Nested class Node
    private class Node {
        T data;
        Node next;  //pointer to the next node

        // Constructor for inner class Node
        Node(T data, Node next) {
            this.data = data;
            this.next = next;
        }

        // Setters & Getters for inner class Node
        public T getData() {
            return data;
        }
        public void setData(T data) {
            this.data = data;
        }
        public Node getNext() {
            return next;
        }
        public void setNext(Node next) {
            this.next = next;
        }
    }

}