Let $\mathcal{U} = \{ [x_1, ..., x_n] \in \mathbb{R}^n : 0 \leq x_i \leq 1\}$ be the unit hypercube and $C \in \mathbb{R}^n\setminus\mathcal{U}$ fixed. Let us consider the following problem $$ \max_{X \in \mathcal{U}} \hspace{0.5cm}\|X - C\|^2.$$
Is there a known polynomial algorithm to solve the above? We can assume that $\|C\|$ is large enough.