The input is an SD file (NOT benzodiazepine as I want to have buckeyball in it) containing 10 records. Each record contains a single connected structure. For each structure, find the longest linear chain of carbon atoms and print each count on its own line.
This one doesn't have a real chemistry goal, except perhaps if you are doing some work with IUPAC nomenclature. It's more meant to show how to work with the basic graph structure of the toolkit, since I don't think this is a built-in function to any of them.
It is possible to do this with a successive number of SMARTS patterns. Count the number of carbons, then do a binary search 1<=i<=N using the SMARTS "[#6]"*i each time. Feel free to do that, but I would like to see something which does the graph traversal manually.