Assigning Unique IDs to Possibly Repeating values in another column (Excel)

Question

The below picture represents the functionality I want: One column (in this case column A) has potential duplicates. I want to assign unique IDs to each duplicate in the right column (in this case column B). I am looking for a function/equation which automatically assigns these unique IDs of the corresponding cell on the left (in this case Column A)

How can I achieve this using an Excel equation?

Answer 1

您应该能够通过将以下公式输入到单元格B2中并向下复制来完成此操作。

=IF(COUNTIF($A$2:A2,A2)>1,VLOOKUP(A2,A:B,2,FALSE),MAX($B$1:B1)+1)