On the Klee's Measure Problem in Small Dimensions

The Klee's measure problem is to compute the volume of the union of a given set of n isothetic boxes in a d-dimensional space. The fastest currently known algorithm for this problem, developed by Over-mars and Yap [6], runs in time O(nd/2 log n). We present an alternative simple approach with the same asymptotic performance. The exposition is restricted to dimensions three and four.