CLASS zcl_hamming DEFINITION PUBLIC.
  PUBLIC SECTION.
    METHODS hamming_distance
      IMPORTING
        first_strand  TYPE string
        second_strand TYPE string
      RETURNING
        VALUE(result) TYPE i
      RAISING
        cx_parameter_invalid.
ENDCLASS.

CLASS zcl_hamming IMPLEMENTATION.

  METHOD hamming_distance.
    " add solution here
  ENDMETHOD.

ENDCLASS.
