A C++ implementation of Booth & Lueker's PQ-Tree algorithm.

Kellog S. Booth, George S. Lueker, Testing for the consecutive ones property,
interval graphs, and graph planarity using PQ-tree algorithms, Journal of
Computer and Systems Sciences, 13(3) (1976) 335-379.

IMPORTANT NOTE: This code currently is known to be buggy on some rare inputs.  A believed to be correct, but harder to use version of this code can be found as a library within BiVoC: https://bioinformatics.cs.vt.edu/~murali/papers/bivoc/

Description of files:
The main file for this library is pqtree.h.  It contains an API that can be
used by client code for dealing with PQ-Trees.  There are two binaries:
fuzztest and pqtest.

pqtest runs the pqtree code for one example set of reductions on a single tree, printing the state of the tree at every step.  This illustrates how the pqtree is built.

fuzztest generates a large random set of possible reductions and runs them
against the library making sure that it never returns false or segfaults.

Usage:
Primarily, this is intended to be used as a library, not a binary.  But you can
still compile and run the binaries |pqtest| and |fuzztest|.  My personal
recommendation would be to compile with scons, http://scons.org/.  To do so,
run:

$ scons
$ ./fuzztest
$ ./pqtest

Alternatively, I also handily include the tried and true MakeFile, so if you
don't have scons on your system and don't feel like installing it, instead just
run:

$ make
$ ./fuzztest
$ ./pqtest