We are given a convex hull CH = {P1, P2,polygon ..., Pn}$C = \{P_1, P_2, \dots, P_n\}$, where the points are ordered either clockwise or counter-clockwise. Additionally, we have a point Pnew = (x, y)$P_\text{new} = (x, y)$ that lies outside the convex hull. The goal is to find the point Pi$P_i$ in CH$C$ that is closest to Pnew$P_\text{new}$ in a "Logarithmic"logarithmic time complexity. (O(log n)$O(\log n)$.)
We can't use sorting because that would take O(nLog(n))$O(n \log(n))$ time, and also we can't use binary search because of the shape of a convex hull and we might delete the half that contains the answer.