Published online by Cambridge University Press: 18 January 2008
Given two trees (a target T and a pattern P) and a natural number w, window embedded subtree problems consist in deciding whether P occurs as an embedded subtree of T and/or finding the number of size (at most) w windows of T which contain pattern P as an embedded subtree. P is an embedded subtree of T if P can be obtained by deleting some nodes from T (if a node v is deleted, all edges adjacent to v are also deleted, and outgoing edges are replaced by edges going from the parent of v (if it exists) to the children of v). Deciding whether P is an embedded subtree of T is known to be NP-complete. Our algorithms run in time O(|T|22|P|) where |T| (resp. |P|) is the size of T (resp. P).