Given k terminals and n axis-parallel rectangular obstacles on the plane, algorithm finds a plane region R* such that, for any point p in R*, the total length of the k shortest rectilinear paths connecting p and the k terminals without passing through any obstacle is minimum. The algorithm is output-sensitive, and takes O((K + n) log(n)) time and O(K + n) space if k is a fixed constant, where K is the total number of polygonal vertices of the found region R*.
