Lew skrev:

snip

Indeed.

And in case anyone's interested, here are the times for HashMap. Looks
like Map is in the league of Set, and not the slow-moving List. (These
times are longer than the previous times because of current CPU
loading; relativity is the key.)

522393 duplicated words. Using java.util.HashSet, time = 789ms.
522393 duplicated words. Using java.util.TreeSet, time = 2168ms.
522393 duplicated words. Using Map , time = 1180ms.
522393 duplicated words. Using java.util.ArrayList, time = 183795ms.
522393 duplicated words. Using java.util.LinkedList, time = 274781ms.

Apologies to Patricia: I see I mis-attributed her post, yet again. And
Lew, I've now become fast friends now with Linux's expand(). Let's see
whether I purged those nasty TABs:

import java.util.*;
import java.io.*;

class Test {
   private static String TEXT_BOOK_NAME = "war-and-peace.txt";

   public static void main(String[] args) {
    try {
       String text = readText();    // Read text into RAM
       countDuplicateWords(text, new HashSet());
       countDuplicateWords(text, new TreeSet());
       countDuplicateWordsMap(text);
       countDuplicateWords(text, new ArrayList());
       countDuplicateWords(text, new LinkedList());
    } catch (Throwable t) {
       System.out.println(t.toString());
    }
   }

   private static String readText() throws Throwable {
    BufferedReader reader =
       new BufferedReader(new FileReader(TEXT_BOOK_NAME));
    String line = null;
    StringBuffer text = new StringBuffer();
    while ((line = reader.readLine()) != null) {
       text.append(line + " ");
    }
    return text.toString();
   }

   private static void countDuplicateWords(String text,
                       Collection listOfWords) {
    int numDuplicatedWords = 0;
    long startTime = System.currentTimeMillis();
    for (StringTokenizer i = new StringTokenizer(text);
        i.hasMoreElements();) {
       String word = i.nextToken();
       if (listOfWords.contains(word)) {
        numDuplicatedWords++;
       } else {
        listOfWords.add(word);
       }
    }
    long endTime = System.currentTimeMillis();
    System.out.println(numDuplicatedWords + " duplicated words. " +
              "Using " + listOfWords.getClass().getName() +
              ", time = " + (endTime - startTime) + "ms.");
   }

   private static void countDuplicateWordsMap(String text) {
    int numDuplicatedWords = 0;
    Map wordsToFrequency = new HashMap();
    long startTime = System.currentTimeMillis();
    for (StringTokenizer i = new StringTokenizer(text);
        i.hasMoreElements();) {
       String word = i.nextToken();
       Integer frequency = (Integer)wordsToFrequency.get(word);
       if (frequency == null) {
        wordsToFrequency.put(word, new Integer(0));
       } else {
        int value = frequency.intValue();
        wordsToFrequency.put(word, new Integer(value + 1));
        numDuplicatedWords++;
       }
    }
    long endTime = System.currentTimeMillis();
    System.out.println(numDuplicatedWords + " duplicated words. " +
              "Using Map " +
              ", time = " + (endTime - startTime) + "ms.");
   }
}

.ed

--

www.EdmundKirwan.com - Home of The Fractal Class Composition

I don't see "colour" (with a U) in there anywhere, Oliver.