Re: find words that contains some specific letters

From:
"John B. Matthews" <nospam@nospam.invalid>
Newsgroups:
comp.lang.java.programmer
Date:
Mon, 01 Jun 2009 07:38:22 -0400
Message-ID:
<nospam-83CE7B.07382201062009@news.aioe.org>
In article
<d121e6f6-6afa-43e7-bcd1-c9a770e12704@z9g2000yqi.googlegroups.com>,
 Fralentino <baretos@gmail.com> wrote:

On 1 Juni, 09:20, Andrew Thompson <andrewtho...@gmail.com> wrote:

On Jun 1, 4:16?pm, Fralentino <bare...@gmail.com> wrote:

...I have a solution for this ..


What is your solution?


My solution:
boolean compareLetters(String toBeCompared,ArrayList<String> letters)
    {

        for(int i = 0;i<toBeCompared.length();i++)
        {
            if(letters.contains(""+toBeCompared.charAt(i)))
            {
                letters.remove(""+toBeCompared.charAt(i));
            }
            else
                return false;
        }
        return true;

    }

IIUC, you then have to run this method on every word in your dictionary.

Another approach is to permute the letters and search the dictionary.
A binary search of an ordered word list is O(log n), worst case.
Here's an example in Ada:

<http://home.roadrunner.com/~jbmatthews/jumble.html>

In Java, permutations can be checked quickly with the contains() method
of the Set interface, once the dictionary is read:

private static final String NAME = "/usr/share/dict/words";
private static final Set<String> set = new TreeSet<String>();
static {
    try {
        File file = new File(NAME);
        BufferedReader in = new BufferedReader(
            new InputStreamReader(new FileInputStream(file)));
        String s;
        while ((s = in.readLine()) != null) {
            set.add(s);
        }
    } catch (IOException ex) {
        System.err.println(ex.getMessage());
    }
}

Finding the permutations of a string in Java is straightforward:

<http://www.google.com/search?q=java+permute>

--
John B. Matthews
trashgod at gmail dot com
<http://sites.google.com/site/drjohnbmatthews>

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