Comments on “algorithms for reporting and counting geometric intersections”

Comments on the paper by Bentley and Ottman (ibid., vol.28, p.643-7, 1979) which presents an algorithm for reporting all <i>K</i> intersections among <i>N</i> planar line segments in 0((<i>N</i>+<i>K</i>) log <i>N</i>) time and 0(<i>N</i>+<i>K</i>) storage. With a small modification that storage requirement can be reduced to 0(<i>N</i>) with no increase in computational time, which is important because <i>K</i> can grow as 0(<i>N</i>²).