// Program to demonstrate the differences between lists and sets

import java.util.*;

public class SetExample {
   public static void main(String[] args) {
      int[] numbers = {18, 5, 3, 7, 18, 4, 9, 12, 9, 3, 6, 10, -5, 42};
      List<Integer> numList = new ArrayList<Integer>();
      Set<Integer> numSet = new TreeSet<Integer>();
      
      for (int n : numbers) {
         numList.add(n);
         numSet.add(n);
      }
      
      System.out.println("list = " + numList);
      System.out.println("set = " + numSet);
      
      //for (int i = 0; i < numList.size(); i++) {
      // for (int n : numList) {
//          if (n % 3 == 0) {
//             numList.remove(n);
//          }
//       }
      Iterator<Integer> listIter = numList.iterator();
      while (listIter.hasNext()) {
         int num = listIter.next();
         if (num % 3 == 0) {
            listIter.remove();
         }
      }
      
      Iterator<Integer> setIter = numSet.iterator();
      while (setIter.hasNext()) {
         int n = setIter.next();
         if (n % 3 == 0) {
            setIter.remove();
         }
      }
      
      System.out.println("list = " + numList);
      System.out.println("set = " + numSet);
   }
}