Indicate Duplicate with Small Time Span? (ID#, Start Date, Stop Date columns)

Hi!

I have a large set of data with 3 columns: ID #, Start Date, Stop Date.

I need to write a formula that will indicate which row, if the ID # appears in the data set twice, has fewer days between Start and Stop Date.

I'm playing around nesting Ifs and Countifs, and would like to ultimately have it return:
- a 0 for rows containing an ID # that isn't repeated
- a 0 for rows with duplicate ID #s that have the longer span between Start Date and Stop Date
- a 1 for rows with a duplicate ID #, that has fewer days between Start and Stop than other occurences of the same ID #


Attached is an example spreadsheet that better explains exactly what I need to do.

Duplicates with Varying Date Ranges.xlsx

As always, thanks for any input!

This is very interesting, but it doesn't do what I need it to - or maybe I don't understand it correctly.

My thought process right now is to use something like: If, CountIf > 1, then Lookup (A1), return Max/Large Column D (Duration)

Well, in case anyone has been following along and is interested: I decided to just add a "Duration" column in D (column C - column B), then Sort, by ID # then Duration, and in column E just use the formula =if(a2=a3,"",1).

Copy+Paste Values, sort by column E, and there's each unique occurence with the longest duration.

Thanks for stoppin'!