//: c08:Statistics.java
// From Thinking in Java, 2nd Edition
// Available at http://www.BruceEckel.com
// (c) Bruce Eckel 1999
// Copyright notice in Copyright.txt
// Simple demonstration of HashMap
import java.util.*;

class Counter { 
  int i = 1; 
  public String toString() { 
    return Integer.toString(i); 
  }
}

class Statistics {
  public static void main(String[] args) {
    HashMap ht = new HashMap();
    for(int i = 0; i < 10000; i++) {
      // Produce a number between 0 and 20:
      Integer r = 
        new Integer((int)(Math.random() * 20));
      if(ht.containsKey(r))
        ((Counter)ht.get(r)).i++;
      else
        ht.put(r, new Counter());
    }
    System.out.println(ht);
  }
} ///:~