SATSolver

A SAT solver implemented in Java using the DPLL algorithm with some optimizations. This project can be run via the CLI and includes a few tests to validate its functionality and correctness.

Note: Around 5,000 benchmark files are bundled with the project. As a result, installation or cloning may take a few minutes.

Installation

Install Java and Maven (if needed)

Make sure Java (16+) and Maven are installed on your system.

• Java Download
• Maven Download

Navigate to the Directory Containing pom.xml

cd SATSolver/

Creating and running

To build the project and generate the .jar file, use:

mvn clean
mvn package

Once the .jar file is built, you can run the solver with:

java -jar path/to/solver/SATSolver-1.0.jar path/to/input.cnf

For example:

java -jar target/SATSolver-1.0.jar benchmarks/20vars/sat/0.cnf
java -jar target/SATSolver-1.0.jar --export

Arguments

filepath, to output results in the command line

--export, to generate results.html, which contains benchmarked results of the solver from the benchmarks folder

Note: Only one of filepath or --export can be used at the same time.

Output Structure

The output is structured as follows:

1. SAT or UNSAT
2. List of true literals, sorted in ascending order by the variable number, or a newline if UNSAT
3. Time taken to initialize the solver
4. Time taken to solve
5. Number of unit propagations that happened during the entire run
6. Depth of the decision tree (number of decision variables)

Other info

Project supports the DIMACS CNF format only

• The benchmarks are located in src/main/resources/benchmarks
• The tests are located in src/test/java/SimpleSATSolverTest.java
• In src/main/java/org/solver:
  • CircularBuffer, IntQueue, and IntStack contain data structures for better performance
  • DimacsParser parses .cnf files (streams)
  • SATInfo contains information printed after the solver finishes
  • SimpleSATSolver contains the solver logic
  • ExportResults exports benchmarks

Time Measurement

• Time is measured in nanoseconds, but the output displays the times in milliseconds.
• If you need the time in nanoseconds, remove the division by 1_000_000 in SATInfo to output time in nanoseconds.