Search Results for "backtracking"

RE2/J is a high-performance regular expression engine implemented in pure Java as a port of Google’s C++ RE2 library. Unlike traditional regex engines such as Java’s java.util.regex, PCRE, or Perl’s implementation—which rely on backtracking and can suffer from catastrophic exponential runtimes—RE2/J guarantees linear-time matching relative to input size. It achieves this efficiency by simulating all possible matches in a single pass using a nondeterministic finite automaton (NFA), ensuring predictable and safe performance even with complex patterns. This makes RE2/J ideal for applications that must handle user-supplied regular expressions securely without the risk of denial-of-service through regex backtracking. ...

LeetCode-Book is a comprehensive study guide for coding interviews that consolidates algorithm patterns, data-structure templates, and worked LeetCode solutions. It organizes problems by topic—arrays, linked lists, stacks/queues, trees/graphs, dynamic programming, greedy, backtracking, and math—so you can study systematically. Explanations are concise but intentional, highlighting why a pattern fits, how to reason about boundary cases, and the time/space trade-offs. Many entries include template code and “swap-in” variations, helping you recognize how the same technique adapts across similar problems. The book also emphasizes problem-solving habits like deriving invariants, choosing appropriate data structures, and verifying with small counterexamples. ...

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. ...

...Animations can be generated on the fly based on user input - for a large selection of algorithms and topic areas, including, but not limited to, the topic areas of backtracking algorithms, compression, cryptography, basing, searching and sorting.

LillyTab is a modular description logic consistency checker (reasoner) with support for a subset of OWL/DL.

...Therefore, with few interfaces implementations you can already run advanced combinatory solutions. Just to name a few algorithms, the Framework can solve any constraints problems using: - Regular Backtracking; - A variety of Backjumping algorithms; - A variety of arc-consistency algorithms; - Local search algorithm; - Tabu search algorithm; - Maximize solutions: comming soon; - Minimize solutions: comming soon; The Framework also enables heuristic injections so that the developers can achieve greater performance of algorithms using their own heuristics. ...

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. ...

The LALR parser generator (LPG) is a tool for developing scanners and parsers written in Java, C++ or C. Input is specified by BNF rules. LPG supports backtracking (to resolve ambiguity), automatic AST generation and grammar inheritance.

JSudoku is a Java version of the game Sudoku. A backtracking algorithm cares for random puzzles and based on the Sudoku-Puzzle JavaScript. Optionally, JSudoku generates X-Sudoku puzzles.