Problem 1: Tetration

https://open.kattis.com/problems/tetration

We want to output $a$ that satisfies:

$N = a^{a^{a^{.^{.^{.}}}}}$

The exponent of the right-hand-side is $a^{a^{.^{.^{.}}}}$, which is equal to $N$as well.

So, $N = a^N \implies a = N^{\frac{1}{N}}$ .

This can be implemented in C++ using the pow(base, exponent) function and doubles.