Duplicate Item Numbers

[lehigh46]

In a privious post I asked the following question;

Column A has hundreds of item numbers.
Most are NOT duplicated, but I could have as many as 10 to 15 item
numbers with duplications and each number could be duplicated 3 to 10
times or more.

Question:

I need a formula for column B which will return a unique number for
each set of duplicates.


As it turns out I gave a poor example of what I needed.

************** Apoligies to Teethless mama ****************

The following is what I really need.

A B
1
2
3
4 1
4 1
4 1
5 2
5 2
6
7
27 5
9
10 3
10 3
10 3
4 1
10 3
10 3
10 3
10 3
24
25 4
25 4
26
27 5
5 2
27 5

Thanks for your help

 

[Roger Govier]

Hi

Then you only need to modify the formula Ron gave to you originally
=IF(COUNTIF($A$1:$A$24,A2)=1,"",COUNTIF($A$1:$A$24,A2))

 

[Domenic]

Assuming that A2:A28 contains the data, try the following formula that
needs to be confirmed with CONTROL+SHIFT+ENTER...

B2, copied down:

=IF(COUNTIF($A$2:$A$28,A2)>1,SUM(IF(COUNTIF($A$2:$A$28,$A$2:$A$28)>1,IF(A
2>$A$2:$A$28,1/COUNTIF($A$2:$A$28,$A$2:$A$28))))+1,"")

Hope this helps!

 

[Guest]

Without sorting your column A values, it'll get tremendously complicated.

Here's what will work if they are sorted:

In cell B2 use the formula
=IF(COUNTIF($A$2:$A$28,A2)=1,"",1)

In cell B3 use this formula & copy it down
=IF(COUNTIF($A$2:$A$28,A3)=1,"",IF(COUNTIF(A$2:A3,A3)>1,VLOOKUP(A3,A$2:B2,2,0),1+MAX(B$2:B2)))