/usr/include/palabos/algorithm/ is in libplb-dev 1.5~r1+repack1-3.
This file is owned by root:root, with mode 0o755.
..
/usr/include/palabos/algorithm/basicAlgorithms.h
/usr/include/palabos/algorithm/basicDataTypes.h
/usr/include/palabos/algorithm/benchmarkUtil.h
/usr/include/palabos/algorithm/benchmarkUtil.hh
/usr/include/palabos/algorithm/functions.h
/usr/include/palabos/algorithm/headers2D.h
/usr/include/palabos/algorithm/headers2D.hh
/usr/include/palabos/algorithm/headers3D.h
/usr/include/palabos/algorithm/headers3D.hh
/usr/include/palabos/algorithm/linearAlgebra.h
/usr/include/palabos/algorithm/linearAlgebra.hh
/usr/include/palabos/algorithm/nonlinearEquationSolvers.h
/usr/include/palabos/algorithm/nonlinearEquationSolvers.hh
/usr/include/palabos/algorithm/quadrature.h
/usr/include/palabos/algorithm/quadrature.hh
/usr/include/palabos/algorithm/spline.h
/usr/include/palabos/algorithm/spline.hh
/usr/include/palabos/algorithm/statistics.h
/usr/include/palabos/algorithm/timePeriodicSignal.h
/usr/include/palabos/algorithm/timePeriodicSignal.hh