“…Colored range searching (also known as "categorical range searching", or "generalized range searching") have been extensively studied in computational geometry since the 1990s. For example, see the papers [6,12,19,20,21,22,24,25,26,27,29,30,31,32,33,35,37,38,39,41,47] and the survey by Gupta et al [23]. Given a set of n colored data points (where the color of a point represents its "category"), the objective is to build data structures that can provide statistics or some kind of summary about the colors of the points inside a query range.…”