Background
Today I gave Atcoder ABC442. In problem E, I observed some analogy of setup of this problem with concepts of Linear Algebra.
Observations
- Monsters are depicted as vectors in $$$\mathbb{R}^2$$$ From a Linear Algebra perspective, every monster $$$i$$$ at coordinates $$$(X_i, Y_i)$$$ is a vector $$$\mathbf{v}_i = \begin{bmatrix} X_i \ Y_i \end{bmatrix}$$$ in the vector space $$$\mathbb{R}^2$$$.Takahashi stands at the origin (the zero vector $$$\mathbf{0}$$$). When he faces a monster, he is aligning his "sight vector" with the subspace spanned by that monster's vector.
