Storing a count in a || array

[michael bradly]

I'm working on a program that reads from a text file, parses each word and sorts them into an Array Based List. In addition I need a parallel array to keep track of how many times a word appears in the text file. So if a word appears more then once, it only goes into the SortedArrayBasedList once and its count is incremented in the parallel array.
I'm having a hard time conceptualizing how to maintain the second array in relation with the first.

while (tokenizer.hasMoreTokens())
{
   word = tokenizer.nextToken();
   aList.sortedAdd(word);
}

After I add the word to my sorted list, I'm a bit befuddled as to how to handle a check to a second array in relation to the first. Any suggestions would be appreciated.
Regards, Michael

[Wirianto Djunaidi]

Well,
the answer is kind of depend on how your
SortedArrayList behave. If it implements
List, it means it accept any object type..
so it's easier to create a wrapper object that
hold your String and the count.
Or you can used the indexing info as your
cross reference to the second array.
Hope that's help.

[Barry Gaunt]

Why don't you use one of the Maps to hold your data?
Your words would be the keys and the counts would be values. The counts would need to be simple objects having an int attribute (counter) and a method to increment that attribute.
-Barry

[michael bradly]

So the idea behind this would be something like

[an][and][the][then]
  1   2    3     4

aList.sortedAdd(word); when word is "then"
if this word matches a word in aList
then aList.getIndex(word)
Then use this index in the second array to increase the count...
if the word is "yet" which doesn't exist
aList.sortedAdd(word);
aList.getIndex(word);
and add 1 to that index in the second array..
And in this type of situation, as the SortedList shifts, I would have to shift the corresponding items in the second array as well? Or is there an easier way of maintaining some handle on the second array without having to shift that as well?
Thanks for the help, Michael

Originally posted by Ryo Saeba:

Or you can used the indexing info as your
cross reference to the second array.
Hope that's help.

[ February 27, 2003: Message edited by: michael bradly ]
[ February 27, 2003: Message edited by: michael bradly ]

[karl koch]

hi
as mentioned before in this thread, i would
use a HashMap to do this.

 
// we will store the words as keys and the 
// count as value in this map 
HashMap map = new HashMap();
// read all your words in a loop here...
String word = .....; // read first word
while (word != null) {
  if (map.get(word) == null) {
    // word isnt in the map yet
    map.put(word, new Integer(1));
  } else {
     // word is in the map, increment the count
     int i = ((Integer)map.get(word)).intValue();
     map.put(word, new Integer(i + 1)); 
  }
   word = ....; // read next word
}

this should give you an idea ... the code is neither compiled nor double checked ;-)

k

[Barry Gaunt]

Karl, rather than using an Integer I would use
a class like:

class Counter
{
    private int counter = 0 ;
    Counter()
    {
    }
    void bump()
    {
        counter++ ;
    }
    int getValue()
    {
        return count ;
    }
    String toString()
    {
        return( "" + counter );
    }
}  

Then I would do: ((Counter)map.get(word)).bump();
I would also use a java.util.TreeMap to do the trick, to save bother of sorting on words at the end. Sorting on word frequeuency is interesting but we'll leave that for now (that is implementing equals() and hashCode() )
-Barry
[ February 27, 2003: Message edited by: Barry Gaunt ]
[ February 27, 2003: Message edited by: Barry Gaunt ]