Word problem with same letters

Hello!

I've made a reasonably efficient solution, it's easy to understand:

import java.util.*;

public class App {

    public static void main(String[] args) {

        String a[] = {"ola","lao","aol","asd","asdf","fdsa"};       
        List<Integer> lista = new ArrayList<Integer>(Collections.nCopies(a.length, 0));

        int num=1;
        for(int i=0; i<a.length; i++){
            if(lista.get(i)==0){
                lista.set(i, num);
                for(int j=i+1; j<a.length; j++)
                    if( lista.get(j)==0 && sameChars(a[i], a[j]))
                        lista.set(j, num);
                num++;
            }
        }

        num--;
        StringBuilder sb[] = new StringBuilder[num];
        for(int i=0; i<num; i++)
            sb[i] = new StringBuilder();


        for(int i=0; i<lista.size(); i++){
            sb[lista.get(i)-1].append(a[i]);
            sb[lista.get(i)-1].append(" ");
        }

        String[] str = new String[sb.length];
        int i=0;
        for(StringBuilder s : sb)
            str[i++] = s.deleteCharAt(s.length()-1).toString();

        imprime(str);
    }


    static boolean sameChars( String firstStr , String secondStr ) {
        char[ ] first  = firstStr.toCharArray( );
        char[ ] second = secondStr.toCharArray( );
        Arrays.sort( first );
        Arrays.sort( second );
        return Arrays.equals( first , second );
    }

    static void imprime(String[] sb) {
        int num = sb.length;
        System.out.print("{");
        for(int i=0; i < num; i++){
            System.out.print("\""+sb[i]+"\"");
            if(i!=num-1)
                System.out.print(", ");
        }
        System.out.print("}");
    }
}

See working at Ideone

Here's a solution:

static String[ ] solution( String[ ] input ) {
    //Solution
    List<Integer> lista = new ArrayList<Integer>( Collections.nCopies( input.length , 0 ) );
    int num = 1;
    boolean _check = false;
    for( int i = 0 ; i < input.length ; i++ ) {
        if( lista.get( i ) == 0 ) {
            lista.set( i , num );
            for( int j = i+1 ; j < input.length ; j++ )
                if( lista.get( j ) == 0 && sameChars( input[ i ] , input[ j ] ) ) {
                    lista.set( j , num );
                    _check = true;
                }

            if( !_check ) 
                lista.set( i , -1 );
            else
                num++;
            _check = false;
        }
    }

    num--;
    StringBuilder sb[ ] = new StringBuilder[ num ];
    for( int i=0 ; i < num ; i++ )
        sb[ i ] = new StringBuilder( );



    for( int i=0 ; i < lista.size( ) ; i++ ) {
        if( lista.get( i ) >= 0 ) {
            sb[ lista.get( i ) - 1 ].append( input[ i ] );
            sb[ lista.get( i ) - 1 ].append(" ");
        }
    }

    String[] str = new String[sb.length];
    int i=0;
    for(StringBuilder s : sb)
        str[i++] = s.deleteCharAt(s.length()-1).toString();


    return str;

}

static boolean sameChars( String firstStr , String secondStr ) {
      char[ ] first  = firstStr.toCharArray( );
      char[ ] second = secondStr.toCharArray( );
      Arrays.sort( first );
      Arrays.sort( second );
      return Arrays.equals( first , second );
}

public static void main( String[ ] args ) {

    String[ ] myStringArray = {"ola","lao","aol","asd","asdf","fdsa"};
    String[ ] output = solution( myStringArray );
    System.out.println( "Solução => " );
    for( int i = 0 ; i < output.length ; i++ ) {
        System.out.println( output[ i ] );
    }

}