Merging row data in Column A has duplicate.

[Nikul Padhya]

I have a worksheet, which has random but Sorted data already.
The column A has all the Id no. and rest of the columns have ether a
blank or a String data.

The Id in Column A can be duplicate in the preceding Row too.

Example
Col1 Col2 Col3
10 A
10 B
11 A
11 C B
11 D

I want to merge the rows only if all the entire data can be copied.
(in case if Id 10)
but incase of Id 11 I want to merge the data such as it does not over
write.
Expected answer

Col1 Col2 Col3
10 A B
11 A B
11 C D

I have some partial knowledge
but I am confused, that should i use multiple for loop to gothrough
the columns again? or the is a function in excel.
Thanks everyone for trying in advance

 

[paul.bellrichard]

Is that really the expected answer?
Why not also include 11 C B?

Col1 Col2 Col3
10 A B
11 A B
11 C B
11 C D

Or why not

Col1 Col2 Col3
10 A B
11 A D
11 C B

Do you want all possible combinations in the final results? Or
anything, as long as all blanks are filled with something
corresponding to another row with the same ID?
Please clarify this seemingly random selection.