(a) Prove $c_2^{(2)}(n)=2\lfloor(n-1) / 2\rfloor+1$, for $n \geq 3$. (See Exercise 6.6 for the definition of $c_k^{(d)}(n)$.)
(b) Prove $c_3^{(2)}(n) \geq \frac{n^2}{3}+c n$, for some real constant $c$.
(c) Prove $c_d^{(d)}(n)=\mathrm{O}\left(n^{d-1}\right)$.