public class SinglyLinkedList { //stores reference to the first node in the list //head is null if the link is empty private Node head; private Node tail; public SinglyLinkedList() { head = null; tail = null; } public boolean isEmpty() { return (head == null); } public void addToFront(int value) { //1) create new node containing the new value Node newNode = new Node(value); //2) link this node to the front of current list newNode.setNext(head); //3) update head to point to new node head = newNode; //4) if the list is empty, make sure to update the tail if(tail ==null) { tail = head; } } // add to back of list public void addToBack(int value) { //special case : if the list is empty if (isEmpty()) { head = new Node(value); tail = head; return; } /* //inneficient method //1)find the last node in the list Node end = head; while(end.getNext() != null) // while end is not the end { end = end.getNext(); } */ //efficient method Node end = tail; //2) add a new node after that node Node newNode = new Node(value); end.setNext(newNode); tail = newNode; } //removes the first node of the list public int removeFront() { // first, check to see if we can remove if (isEmpty()) { throw new IllegalStateException("cannot remove from an empty list"); } //grab value before removal int ret = head.getValue(); //just skip the first node head = head.getNext(); //update tail if necessary // if (head == null) { tail = null; } //return removed values return ret; } //print method public String toString() { //goal: print out everything in the list, separated by spaces //using a StringBuilder // when created, sb is empty //like: String ret = ""; StringBuilder sb = new StringBuilder(); //lets add the first element to our string int firstValue = head.getValue(); /* //ret+= firstvalue sb.append(firstValue); */ for (Node tmp = head; tmp != null; tmp = tmp.getNext()) { sb.append(tmp.getValue() + " "); } return sb.toString(); } //private inner class private class Node{ //private variables private int value; // the value private Node next; // reference to next node //constructors public Node(int value, Node next) { this.value = value; this.next = next; } public Node(int value) { this(value, null); }

//getters and setters public int getValue() { return value; }

public void setValue(int value) { this.value = value; }

public Node getNext() { return next; }

public void setNext(Node next) { this.next = next; } }

}

l. New Methods Add the following methods to the SinglyLinkedList class: A method min) that returns the smallest element in the list. . A method max) that returns the largest element in the list. A method removeLast() that removes the last node in list and returns its value. If the list is empty, calling any of these methods should throw an IllegalStateException