In Java implement the method ListsswapLargestAndsecondsmalle

In Java, implement the method Lists.swapLargestAndsecondsmallest (ArrayList a) that swaps the largest and second smallest element in a. If there are multiple largest or second smallest elements, pick the first one. If all elements are the same, don\'t change anything. Your algorithm should be O(n). Check your answer with CodeCheck

Solution

//ArrayListDemo.java
import java.util.ArrayList;
import java.util.Iterator;

public class ArrayListDemo
{
   public static void main(String args[])
   {
       // Creating an ArrayList
       ArrayList al = new ArrayList();
       System.out.println(\"Initial size of ArrayList: \" + al.size()); //0
      
       //Add elements to the ArrayList
       al.add(\"Red\");
       al.add(\"Green\");
       al.add(\"Blue\");
       al.add(\"Pink\");
       al.add(\"Orange\");
      
       System.out.println(\"\ Size of ArrayList after additions: \" + al.size()); //5

       //Display the ArrayList
       System.out.println(\"\ Contents of ArrayList After add: \" + al);
      
       // Remove elements from ArrayList      
       al.remove(4);
       System.out.println(\"\ Contents of ArrayList after remove index: \" + al);

       al.remove(\"Pink\");
       System.out.println(\"\ Contents of ArrayList after remove object: \" + al);      
       System.out.println(\"\ Size of ArrayList after deletions: \" + al.size());
      
       // Display the ArrayList
       System.out.println(\"\ Contents of ArrayList after modification: \" + al);
      
       StringBuffer sb        = new StringBuffer();

       String alElement    = (String)(al.get(1));
       System.out.println(\"alElement :\"+alElement);

       al.add(alElement+\" rose\");
       System.out.println(al);
      
       System.out.println(\"al elements through Iterator\");
       Iterator alIterator = al.iterator();      
       while(alIterator.hasNext())
       {
           String str = (String)alIterator.next();
           System.out.println(str);
           sb.append(str+\",\");
       }
      
       System.out.println(\"Array List values in string buffer :\"+sb);
   }
}