Contributors: Serge Gaspers, Joachim Gudmundsson, Mitchell Jones, Julian Mestre, Stefan Rummele.

This source code is distributed under the open source MIT license.

1. Compile with make.

2. Run the code by using the tw-heuristic script (may need to chmod beforehand to give executable permissions).

This script accepts one argument.

./tw-heuristic -s [seed]

where [seed] is a given seed. If nothing is given, a seed will be randomly generated and used. All instance data is passed via stdin, and output is printed to stdout.

During processing, whenever a better tree decomposition is found, a status update will be printed in the form of

c status [width + 1] [current time]

where [width + 1] is the width of the best tree decomposition found so far plus one, and [current time] is the current Unix time in milliseconds.

3. Test it with an example.

   ./tw-heuristic -s 4321 < example.gr

This will output a tree decomposition.

c status 2 1469500579541
s td 5 2 5
b 1 2 1
b 2 3 2
b 3 4 5
b 4 3 4
b 5 3
1 2
3 4
2 5
4 5

4. At any time you can send the script the UNIX signal SIGTERM in order to terminate the program and immediately print out the best tree decomposition found. This can be triggered with

   kill -SIGTERM [pid]

where [pid] is the pid of the script tw-heuristic (not the Java process running in the background).

Note: Requires Java 7 or higher.