FUNCTION {{p}}track_fee
  IMPORTING
    it_paths TYPE STANDARD TABLE
  EXPORTING
    et_fees TYPE STANDARD TABLE
  EXCEPTIONS
    invalid_distance
    invalid_category.

  TYPES: BEGIN OF ty_sum,
           train_cat  TYPE c LENGTH 2,
           path_count TYPE i,
           total_km   TYPE p LENGTH 13 DECIMALS 2,
           total_fee  TYPE p LENGTH 13 DECIMALS 2,
         END OF ty_sum.

  DATA: lt_sums TYPE SORTED TABLE OF ty_sum WITH UNIQUE KEY train_cat,
        lv_cat  TYPE c LENGTH 2,
        lv_km   TYPE p LENGTH 13 DECIMALS 2,
        lv_flag TYPE c LENGTH 1,
        lv_rate TYPE p LENGTH 5 DECIMALS 2,
        lv_raw  TYPE decfloat34,
        lv_fee  TYPE p LENGTH 13 DECIMALS 2.

  FIELD-SYMBOLS: <ls_in>  TYPE any,
                 <ls_out> TYPE any,
                 <ls_sum> TYPE ty_sum,
                 <lv_val> TYPE any.

  CLEAR et_fees.

  LOOP AT it_paths ASSIGNING <ls_in>.
    ASSIGN COMPONENT 'TRAIN_CAT' OF STRUCTURE <ls_in> TO <lv_val>.
    lv_cat = <lv_val>.
    ASSIGN COMPONENT 'DISTANCE_KM' OF STRUCTURE <ls_in> TO <lv_val>.
    lv_km = <lv_val>.
    ASSIGN COMPONENT 'NIGHT_FLAG' OF STRUCTURE <ls_in> TO <lv_val>.
    lv_flag = <lv_val>.

    IF lv_km <= 0.
      RAISE invalid_distance.
    ENDIF.

    CASE lv_cat.
      WHEN 'IC'.
        lv_rate = '1.20'.
      WHEN 'RG'.
        lv_rate = '0.90'.
      WHEN 'FR'.
        lv_rate = '0.60'.
      WHEN 'SP'.
        lv_rate = '1.50'.
      WHEN OTHERS.
        RAISE invalid_category.
    ENDCASE.

    lv_raw = lv_km * lv_rate.
    IF lv_flag = 'X'.
      lv_raw = lv_raw * 12 / 10.
    ENDIF.
    lv_fee = round( val = lv_raw dec = 2 mode = cl_abap_math=>round_half_up ).
    IF lv_fee < 5.
      lv_fee = 5.
    ENDIF.

    READ TABLE lt_sums ASSIGNING <ls_sum> WITH TABLE KEY train_cat = lv_cat.
    IF sy-subrc <> 0.
      INSERT VALUE ty_sum( train_cat = lv_cat ) INTO TABLE lt_sums ASSIGNING <ls_sum>.
    ENDIF.
    <ls_sum>-path_count = <ls_sum>-path_count + 1.
    <ls_sum>-total_km   = <ls_sum>-total_km + lv_km.
    <ls_sum>-total_fee  = <ls_sum>-total_fee + lv_fee.
  ENDLOOP.

  LOOP AT lt_sums ASSIGNING <ls_sum>.
    APPEND INITIAL LINE TO et_fees ASSIGNING <ls_out>.
    ASSIGN COMPONENT 'TRAIN_CAT' OF STRUCTURE <ls_out> TO <lv_val>.
    <lv_val> = <ls_sum>-train_cat.
    ASSIGN COMPONENT 'PATH_COUNT' OF STRUCTURE <ls_out> TO <lv_val>.
    <lv_val> = <ls_sum>-path_count.
    ASSIGN COMPONENT 'TOTAL_KM' OF STRUCTURE <ls_out> TO <lv_val>.
    <lv_val> = <ls_sum>-total_km.
    ASSIGN COMPONENT 'TOTAL_FEE' OF STRUCTURE <ls_out> TO <lv_val>.
    <lv_val> = <ls_sum>-total_fee.
  ENDLOOP.

ENDFUNCTION.