Where f(n) = n! belongs to? P, co-P, NPComplete or NPHard?

  • $\begingroup$ do you define $f(n)$ as a complexity function? what exactly are you asking? $\endgroup$
    – lox
    Mar 31, 2019 at 14:07
  • 1
    $\begingroup$ Have a look at the definitions. As a starter, is "f(n) = n!" a decision problem? $\endgroup$
    – Juho
    Mar 31, 2019 at 14:08
  • $\begingroup$ A decision problem would be "given n and x, is n! = x?" How much time would it take you to decide that? In the non-decision problem "Given n, what is n! in decimal notation", how large would be the output, compared to the size of the input? Can that problem be solved in polynomial time? $\endgroup$
    – gnasher729
    Mar 31, 2019 at 14:57


Browse other questions tagged or ask your own question.