Find the second largest element in a linked list in java

Java program for Find the second largest element in a linked list. Here problem description and other solutions.

// Java Program for
// Find second largest number in linked list

// Linked list node
class LinkNode
{
    public int data;
    public LinkNode next;
    public LinkNode(int data)
    {
        this.data = data;
        this.next = null;
    }
}
public class SingleLL
{
    public LinkNode head;
    public LinkNode tail;
    public SingleLL()
    {
        // Set head and tail 
        this.head = null;
        this.tail = null;
    }
    // Add new node at the end of linked list
    public void insert(int value)
    {
        // Create a new node
        LinkNode node = new LinkNode(value);
        if (this.head == null)
        {
            this.head = node;
        }
        else
        {
            this.tail.next = node;
        }
        this.tail = node;
    }
    // Display linked list element
    public void display()
    {
        if (this.head == null)
        {
            return;
        }
        LinkNode temp = this.head;
        // iterating linked list elements
        while (temp != null)
        {
            System.out.print(temp.data + " → ");
            // Visit to next node
            temp = temp.next;
        }
        System.out.println("null");
    }
    // Find second largest node in linked list
    public void secondLargest()
    {
        if (this.head == null)
        {
            System.out.println("\nEmpty linked list");
            return;
        }
        // Display given linked list element
        this.display();
        // Define some auxiliary variables
        LinkNode big = null;
        LinkNode result = null;
        LinkNode temp = this.head;
        // iterating linked list elements
        while (temp != null)
        {
            if (big == null)
            {
                // Get first node
                big = temp;
            }
            else if (big.data < temp.data)
            {
                // Get a new big node
                // Get second largest node
                result = big;
                // Get current largest node
                big = temp;
            }
            else if (big.data != temp.data)
            {
                if (result == null)
                {
                    // If in case second largest node empty
                    result = temp;
                }
                else if (result.data < temp.data)
                {
                    // Get new second largest node
                    result = temp;
                }
            }
            // Visit to next node
            temp = temp.next;
        }
        if (result == null)
        {
            // When second largest node are not exist in linked list
            System.out.println("Second largest element are not exist");
        }
        else
        {
            System.out.println("Second largest : " + result.data);
        }
    }
    public static void main(String[] args)
    {
        // Testing linked list
        SingleLL list1 = new SingleLL();
        SingleLL list2 = new SingleLL();
        SingleLL list3 = new SingleLL();
        SingleLL list4 = new SingleLL();

        // Add node in first linked list
        // 6 → 4 → 5 → 10 → 3 → 7 → 9 → 2 → 8 → null
        list1.insert(6);
        list1.insert(4);
        list1.insert(5);
        list1.insert(10);
        list1.insert(3);
        list1.insert(7);
        list1.insert(9);
        list1.insert(2);
        list1.insert(8);
        list1.secondLargest();
        // Add node in second linked list
        // 1 → 1 → 4 → 2 → 3 → 1 → null
        list2.insert(1);
        list2.insert(1);
        list2.insert(4);
        list2.insert(2);
        list2.insert(3);
        list2.insert(1);
        list2.secondLargest();

        // Add node in third linked list
        // 2 → 6 → 8 → 4 → 8 → 3 → 3 → 2 → null
        list3.insert(2);
        list3.insert(6);
        list3.insert(8);
        list3.insert(4);
        list3.insert(8);
        list3.insert(3);
        list3.insert(3);
        list3.insert(2);
        list3.secondLargest();
        // Add node in fourth linked list
        list4.insert(2);
        list4.insert(2);
        list4.insert(2);
        // 2 → 2 → 2 → null
        list4.secondLargest();
    }
}

Output

6 → 4 → 5 → 10 → 3 → 7 → 9 → 2 → 8 → null
Second largest : 9
1 → 1 → 4 → 2 → 3 → 1 → null
Second largest : 3
2 → 6 → 8 → 4 → 8 → 3 → 3 → 2 → null
Second largest : 6
2 → 2 → 2 → null
Second largest element are not exist