Excel 2007 : double sided match between two columns....

[tbeltramo]

I want to match pairs contemporaneously from two different columns. Imagine two columns with a set of numbers. A( 1, 3, 4, 5) and B (3, 1, 5, 6) Such that A1:B1 pair is 1:3 and A2:B2 pair is 3:1; A3:B3 pair is 4:5, etc. Now I want to write a formula in column C which is equal to 1 when Column A=B has a matching pair for Column B=A. I.E. take the first two rows A1, B1 and A2, B2. This is an example when there is a dual sided match (1:3) for A1:B1 and (3:1) for B1:A1. For Row 3 and 4 there is no double sided match thus the formula should yield 0.

Can you help me? THANKS

[DonkeyOte]

It's not clear if you're always comparing rows 1 to 2 and 3 to 4 etc or if in fact the "pair" might appear far apart from one another ?
(and if there may be > 1 match)

One possibility given XL2007 might be:

C1: =SIGN(COUNTIFS($A$1:$A$10;$B1;$B$1:$B$10;$A1))
copied down

If you always comparing in pairs of rows (1:2, 3:4, 5:6) let us know.