Given tree T on n vertices, how many k -colorings does it have that use all k colors? HELP!!!

Revision en1, by cosmere, 2021-10-20 20:46:56

I am trying to solve this problem. The editorial for this problem uses the following approach

Can anyone explain me the Inclusion-Exclusion formula shown here?


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en1 English cosmere 2021-10-20 20:46:56 376 Initial revision (published)