CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

Build System

This project uses Bazel as its build system (requires JDK 8+). Dependencies are managed via Maven through rules_jvm_external and declared in MODULE.bazel.

Commands

Run all tests:

bazel test //src/test/...

Run tests for a specific package:

bazel test //src/test/java/com/williamfiset/algorithms/graphtheory:all
bazel test //src/test/java/com/williamfiset/algorithms/sorting:all

Run a single test class:

bazel test //src/test/java/com/williamfiset/algorithms/graphtheory:BoruvkasTest

Run a specific algorithm (with main method):

bazel run //src/main/java/com/williamfiset/algorithms/graphtheory:BinarySearch
bazel run //src/main/java/com/williamfiset/algorithms/search:BinarySearch

Alternative (without Bazel):

mkdir classes
javac -sourcepath src/main/java -d classes src/main/java/com/williamfiset/algorithms/search/BinarySearch.java
java -cp classes com.williamfiset.algorithms.search.BinarySearch

Project Structure

src/
  main/java/com/williamfiset/algorithms/
    datastructures/   # Data structure implementations
    dp/               # Dynamic programming algorithms + examples/
    geometry/         # Computational geometry
    graphtheory/      # Graph algorithms
      networkflow/    # Max flow, min cost flow, bipartite matching
      treealgorithms/ # Tree-specific algorithms (LCA, rooting, isomorphism)
    linearalgebra/    # Matrix operations
    math/             # Number theory, primes, FFT
    other/            # Miscellaneous (bit manipulation, permutations, etc.)
    search/           # Search algorithms
    sorting/          # Sorting algorithms
    strings/          # String algorithms
    utils/            # Shared utilities
      graphutils/     # Graph construction helpers

  test/java/com/williamfiset/algorithms/
    <mirrors main structure>

Architecture Patterns

BUILD files: Every package has a Bazel BUILD file. The main source BUILD files define a java_library target (named after the package, e.g., graphtheory) plus individual java_binary targets per class. Test BUILD files define java_test targets per test class using JUnit 5 via ConsoleLauncher.

Test framework: Tests use JUnit 5 (Jupiter) with some legacy JUnit 4. New tests should use JUnit 5.

Graph representation: Most graph algorithms accept adjacency lists built with List<List<Edge>> or similar structures. Many solvers are implemented as classes where you construct the solver, add edges, then call a solve() method.

Network flow base: Flow algorithms in networkflow/ share a common abstract solver pattern — NetworkFlowSolverBase is extended by concrete implementations (Dinic's, Ford-Fulkerson, etc.).

When adding a new algorithm:

1. Add the .java file in the appropriate src/main/java/... package
2. Add a java_binary entry in that package's BUILD file
3. Add a test file in the corresponding src/test/java/... package
4. Add a java_test entry in the test BUILD file
5. Update README.md with the new algorithm entry