import java.util.*;

class UseArrayLists7
// Shows adding an integer after all occurrences of an integer 
// constructively in an ArrayList (improved method)
{
 public static void main(String[] args) throws Exception
 {
  Scanner input = new Scanner(System.in);
  System.out.println("Enter some numbers (all on one line, separated by spaces):");
  String line = input.nextLine();
  String[] numbers = line.split(" ");
  ArrayList<Integer> a = new ArrayList<Integer>();
  for(int i=0; i<numbers.length; i++)
      a.add(new Integer(numbers[i]));
  System.out.println("The numbers are stored in an ArrayList");
  System.out.println("\nThe ArrayList is "+a);
  System.out.print("\nEnter two numbers: ");
  int p = input.nextInt(), q=input.nextInt();
  System.out.println("Add "+q+" after every "+p+" in the ArrayList");
  ArrayList<Integer> b=addAfter(a,p,q);
  System.out.println("\nThe ArrayList created is "+b);
  System.out.println("The original ArrayList is still "+a);
 }

 public static ArrayList<Integer> addAfter(ArrayList<Integer> a,Integer m,Integer n)
 // Adds n after every occurrence of m in a, constructively.
 // Avoids calling a.get(i) twice.
 {
  ArrayList<Integer> b = new ArrayList<Integer>();
  for(int i=0; i<a.size(); i++)
    {
     Integer k=a.get(i);
     b.add(k);
     if(k.equals(m))
       b.add(n);
    }
  return b;
 }
}