Count distinct elements in a Vector : Vector « Collections « Java Tutorial

1. Java Tutorial
2. Collections
3. Vector

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

public class Main {
  public static void main(String[] argv) {
    List<String> list = new ArrayList<String>();
    list.add("A");
    list.add("2");
    list.add("c2");
    
    System.out.println(countDistinctElements(list, 0, list.size()));
  }

  static int countDistinctElements(List source, int position, int count){
    List list = source.subList(position, position + count);
    Set set = new HashSet();
    set.addAll(list);
    return set.size();
  }
}