UVA - 642 - Word Amalgamation

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.HashSet;

public class Main {

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringBuffer sb = new StringBuffer("");
        String m = "";
        HashSet<String> hs=new HashSet<String>();
        while ((m = br.readLine()) != null) {
            if ("XXXXXX".equals(m)) {
                break;
            }
            hs.add(m);
        }
        boolean enter=false;
        while ((m = br.readLine()) != null) {  
            if ("XXXXXX".equals(m)) {
                break;
            }
            char[]arr=m.toCharArray();
            boolean[]temp=new boolean[arr.length];
            Arrays.sort(arr);
            String arrS=new String(arr);
            StringBuilder tempSb=new StringBuilder();
            permutationsChar(0,arrS,temp,arr,hs,tempSb);
            if(tempSb.toString().equals("")){
               sb.append("NOT A VALID WORD\n");
            }else{
               sb.append(tempSb);
            }
            sb.append("******\n");
        }
        System.out.print(sb);
    }

    public static void permutationsChar(int i, String s, boolean[] v, char[] res, HashSet<String> hs,StringBuilder sb) {
        if (i == res.length) {
            String temp=new String(res);
            if(hs.contains(temp)){
                sb.append(temp).append("\n");
            }
        } else {
            for (int j = 0; j < s.length(); j++) {
                if (!v[j]) {
                    if ((j > 0 && !v[j - 1] && s.charAt(j - 1) == s.charAt(j))) {
                        continue;
                    }
                    v[j] = true;
                    res[i] = s.charAt(j);
                    permutationsChar(i + 1, s, v, res, hs,sb);
                    v[j] = false;
                    res[i] = '-';
                }
            }
        }
    }
}