Re: find words that contains some specific letters

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>