Search Results for "backtracking"

Tool to transcribe Parsing Expression Grammar into a parser written in Java. Parsing Expression Grammar (PEG) is a way to specify recursive-descent parsers with limited backtracking. The use of backtracking lifts the LL(1) restriction usually imposed by top-down parsers. In addition, PEG can define parsers with integrated lexing. Unlike some existing parser generators for PEG, the tool does not produce a complex and storage-hungry "packrat parser", but a collection of transparent recursive procedures. ...

The subgraph matching problem (subgraph isomorphism) is NP-complete. Previously, we designed an exact subgraph matching (ESM) algorithm for dependency graphs using a backtracking approach (http://esmalgorithm.sourceforge.net). We further designed an approximate subgraph matching (ASM) algorithm that is capable of detecting approximate subgraph matching based on a subgraph distance. Assume that the graph G and the subgraph Gs have m and n vertices, and km and kn edges respectively, the total worst-case algorithm complexity is O(m^n * n(n-1)/2 * km * log m). ...

The subgraph matching problem (subgraph isomorphism) is NP-complete. We designed a simple exact subgraph matching (ESM) algorithm for dependency graphs using a backtracking approach. The total worst-case algorithm complexity is O(n^2 * k^n) where n is the number of vertices and k is the vertex degree. We have demonstrated the successful usage of our algorithm in three biomedical relation and event extraction applications: BioNLP 2011 shared tasks on event extraction, Protein-Residue association detection and Protein-Protein interaction identification. ...