这是一种非递归的方法,您可能必须重写使用新的 740 语法的部分。这个想法非常简单,首先将数据转换为一个内部表,每个参数一个条目,其中包含一个带有可能值的表,即 LOOP 循环。从那里可以很简单地完成所有组合并将它们添加到另一个内部表,即 WHILE 循环。
REPORT z_algorithm.
TYPES: ty_param TYPE char1,
ty_value TYPE char2,
BEGIN OF ty_struct,
x TYPE ty_param,
y TYPE ty_value,
END OF ty_struct,
BEGIN OF ty_combi,
z TYPE i,
s TYPE ty_struct,
END OF ty_combi.
TYPES: BEGIN OF ty_param_struct,
x TYPE ty_param,
ys TYPE STANDARD TABLE OF ty_value WITH DEFAULT KEY,
ix TYPE i,
END OF ty_param_struct.
DATA: tab TYPE STANDARD TABLE OF ty_struct,
params TYPE STANDARD TABLE OF ty_param_struct,
done TYPE abap_bool VALUE abap_false,
z TYPE i VALUE 0,
overflow TYPE abap_bool VALUE abap_false,
combis TYPE STANDARD TABLE OF ty_combi.
START-OF-SELECTION.
APPEND VALUE: #( x = 'A' y = 'a1' ) TO tab,
#( x = 'A' y = 'a2' ) TO tab,
#( x = 'A' y = 'a3' ) TO tab,
#( x = 'B' y = 'b1' ) TO tab,
#( x = 'B' y = 'b2' ) TO tab,
#( x = 'C' y = 'c1' ) TO tab,
#( x = 'C' y = 'c2' ) TO tab.
LOOP AT tab ASSIGNING FIELD-SYMBOL(<tab>).
READ TABLE params WITH KEY x = <tab>-x ASSIGNING FIELD-SYMBOL(<param>).
IF sy-subrc NE 0.
APPEND INITIAL LINE TO params ASSIGNING <param>.
<param>-x = <tab>-x.
<param>-ix = 1.
ENDIF.
APPEND <tab>-y TO <param>-ys.
ENDLOOP.
WHILE done EQ abap_false.
ADD 1 TO z.
overflow = abap_true.
done = abap_true.
LOOP AT params ASSIGNING <param>.
READ TABLE <param>-ys INDEX <param>-ix ASSIGNING FIELD-SYMBOL(<y>).
APPEND VALUE #( z = z s-x = <param>-x s-y = <y> ) TO combis.
IF overflow EQ abap_true.
ADD 1 TO <param>-ix.
ENDIF.
IF <param>-ix GT lines( <param>-ys ).
overflow = abap_true.
<param>-ix = 1.
ELSE.
overflow = abap_false.
done = abap_false.
ENDIF.
ENDLOOP.
ENDWHILE.