question: private static String [ ] formGrams ( String text , int ng ) { int len = text . length ( ) ; String [ ] res = new String [ len - ng + 1 ] ; for ( int i = 0 ; i < len - ng + 1 ; i ++ ) { res [ i ] = text . substring ( i , i + ng ) ; } return res ; }
target:  Form all ngrams for a given word.