Module 4: Index Structures
Lecture 15: Range Trees and Interval Trees
Windowing queries
Return all (axis-parallel) segments that are visible through the query window
Segments which have one (or two) endpoints in the window can be searched using range trees
Bookkeeping to avoid duplication of segments with both end-points in the window
Stabbing queries to nd out lines (equivalently points) that cut a particular arm
of the window
Line
is equivalent to the point
Interval tree to search these
of the window
is equivalent to the point 
