text: If frequency of S [ i ] is greater than 1 or it is outside the range
code: if ( S . charAt ( i ) >= ( ' a ' + Math . min ( N , 25 ) ) || ( M . containsKey ( S . charAt ( i ) ) && M . get ( S . charAt ( i ) ) > 1 ) ) { if ( V . get ( j ) < S . charAt ( i ) ) continue ;