  We consider the so called hyperon puzzle of neutron star (NS). We employ
Skyrme force models for the description of in-medium nucleon-nucleon,
nucleon-Lambda hyperon ($N\Lambda$), and Lambda-Lambda ($\Lambda\Lambda$)
interactions. A phenomenological finite-range force for the $\Lambda\Lambda$
interaction is considered as well. Equation of state (EoS) of NS matter is
obtained in the framework of density functional theory, and
Tolman-Oppenheimer-Volkoff equations are solved to obtain the mass-radius
relations of NSs. It has been generally known that the existence of hyperons in
the NS matter is not well supported by the recent discovery of large-mass NSs
($M \simeq 2 M_\odot$) since hyperons make the EoS softer than the one without
them. For the selected interaction models, $N\Lambda$ interactions reduce the
maximum mass of NS by about 30~\%, while $\Lambda\Lambda$ interactions can give
about 10~\% enhancement. Consequently, we find that some Skyrme force models
predict the maximum mass of NS consistent with the observation of $2 M_\odot$
NSs, and at the same time satisfy observationally constrained mass-radius
relations.
