A Nettree for pattern Matching with flexible wildcard Constraints

In this paper, a new nonlinear structure called Nettree is proposed. A Nettree is different from a tree in that a node may have more than one parent. An algorithm, named Nettree for pattern Matching with flexible wildcard Constraints (NAMEIC), based on Nettree is designed to solve pattern matching with flexible wildcard constraints. The problem is exponential with regard to the pattern length m. We prove the correctness of the algorithm, and illustrate how it works through an example. NAMEIC is W*m times faster than an existing approach because the result can be given after creating the Nettree in one pass, where W is the maximal gap flexibility. Experiments validate the correctness and efficiency of NAMEIC.