Question

import java.io.*;
import java.util.Scanner;

class Node {
int data;
Node next;
Node(int d){ // Constructor
   data = d;
   next = null;
}
}

class ACOLinkedList {// a Singly Linked List
   Node head; // head of list
   public void insert(int data){ // Method to insert a new node
       Node new_node = new Node(data); // Create a new node with given data
       new_node.next = null;
       if (head == null) // If the Linked List is empty, then make the new node as head
           head = new_node;
       else {// Else traverse till the last node and insert the new_node there
           Node last = head;
           while (last.next != null)
               last = last.next;
           last.next = new_node; // Insert the new_node at last node
       }
   }
}

class Main {
public static void main(String[] args)
   {
       ACOLinkedList list = new ACOLinkedList();/* Start with the empty list. */
       Scanner scan = new Scanner(System.in);
       int num;
       for (int i=0; i<10; i++){//Read list values
           num = scan.nextInt();
           list.insert(num);
       }
System.out.println(""+getSecondMax(list));
   }

   
public static int getSecondMax(ACOLinkedList list) {
       //TODO: Find the second largest element in the list (list could have any number of elements)
       //Example: if list={40, 20, 25, 15, 99}, the method should return: 40
  
      
   }

}

Answer 1

METHOD IN JAVA :

public static int getSecondMax(ACOLinkedList list) {
   
   ACOLinkedList temp=list;
   Node t=temp.head;

   int max1= Integer.MIN_VALUE;
   int max2= Integer.MIN_VALUE;


   while(t!=null)
   {
      if(t.data>max1)
      {
         max2=max1;
         max1=t.data;
      }

      else if(t.data>max2&&t.data!=max1)
         max2=t.data;

      t=t.next;
   }

   // to indicate there is no second largest element present , we returns -1
   if(max2== Integer.MIN_VALUE)
      return -1;

   //else return the second largest element
   else
      return max2;

}

WHOLE CODE TOGETHER :

import java.io.*;
import java.util.Scanner;

class Node {
   int data;
   Node next;
   Node(int d){ // Constructor
      data = d;
      next = null;
   }
}

class ACOLinkedList {// a Singly Linked List
   Node head; // head of list
   public void insert(int data){ // Method to insert a new node
      Node new_node = new Node(data); // Create a new node with given data
      new_node.next = null;
      if (head == null) // If the Linked List is empty, then make the new node as head
         head = new_node;
      else {// Else traverse till the last node and insert the new_node there
         Node last = head;
         while (last.next != null)
            last = last.next;
         last.next = new_node; // Insert the new_node at last node
      }
   }
}

public class Main {
   public static void main(String[] args) {
      ACOLinkedList list = new ACOLinkedList();/* Start with the empty list. */
      Scanner scan = new Scanner(System.in);
      int num;
      for (int i = 0; i < 10; i++) {//Read list values
         num = scan.nextInt();
         list.insert(num);
      }
      System.out.println("" + getSecondMax(list));
   }


   public static int getSecondMax(ACOLinkedList list) {
      
      ACOLinkedList temp=list;
      Node t=temp.head;

      int max1= Integer.MIN_VALUE;
      int max2= Integer.MIN_VALUE;


      while(t!=null)
      {
         if(t.data>max1)
         {
            max2=max1;
            max1=t.data;
         }

         else if(t.data>max2&&t.data!=max1)
            max2=t.data;

         t=t.next;
      }

      // to indicate there is no second largest element present , we returns -1
      if(max2== Integer.MIN_VALUE)
         return -1;

      //else return the second largest element
      else
         return max2;

   }
}

EXAMPLE OF ABOVE CODE :