how to extract common file path from list of file paths in c#

Question

What is the best way extract the common file path from the list of file path strings in c#?

Eg: I have a list 5 file paths in List variable, like below

c:\

Answer 1

I don't think there's a "trick"to get past using the brute force method to do this comparison, but you can optimize your solution somewhat:

Prepare:
Find the shortest string

Repeat:
See if all of the other strings contain it
If so, you're done
If not, remove one or more characters