/**
 * ========================================================================
 * TestHashSet.javat: Use a HashSet to print all unique words in System.in.
 * 
 * Author: Cay Horstmann
 * ========================================================================
 */

import java.util.*;

public class TestHashSet {
   public static void main(String[] args) {
      Set<String> words = new HashSet<String>(); // HashSet implements Set
      long totalTime = 0;

      // Use a Scanner to read words from standard input.
      // Keep track of the time, measured in milliseconds.

      Scanner in = new Scanner(System.in);
      while (in.hasNext()) {
         String word   = in.next();
         long callTime = System.currentTimeMillis();
         words.add(word);
         callTime = System.currentTimeMillis() - callTime;
         totalTime += callTime;
      }

      // Print up to the first 20 words ....

      System.out.println("Print up to the first 20 distinct words ");
      System.out.println("======================================= ");

      Iterator<String> iter = words.iterator();
      for (int i = 1; i <= 20 && iter.hasNext(); i++)
         System.out.println(iter.next());

      // Print number of distinct words ...

      System.out.println("======================================= ");
      System.out.println(words.size() + " distinct words. " + totalTime + " milliseconds.");
      System.out.println("======================================= ");
   }
}