*Andreas Fabri*

This chapter presents the interval skip list introduced by Hanson [Han91], and derived from the skip list data structure [Pug90].

The data structure stores intervals and allows to perform stabbing queries, that is to test whether a point is covered by any of the intervals. It further allows to find all intervals that contain a point.

The interval skip list is, as far as its functionality is concerned,
related to the *Segment_tree*. Both allow to do stabbing queries
and both allow to find all intervals that contain a given point. The
implementation of segment trees in CGAL works in higher
dimensions, whereas the interval skip list is limited to the 1D
case. However, this interval skip list implementation is fully
dynamic, whereas the segment tree implementation in CGAL is
static, that is all intervals must be known in advance.

This package has one concept, namely for the interval with which the interval skip list class is parameterized.

*CGAL::Interval_skip_list<Interval>*

*CGAL::Interval_skip_list_interval<Value>*

*CGAL::Level_interval<FaceHandle>*

Interval_skip_list<Interval> |

Interval_skip_list_interval<Value> |

Interval |

Level_interval<FaceHandle> |

Next chapter: dD Spatial Searching