  We introduce a rejection-free, flat histogram, cluster algorithm to determine
the density of states of hard-core lattice gases. We show that the algorithm is
able to efficiently sample low entropy states that are usually difficult to
access, even when the excluded volume per particle is large. The algorithm is
based on simultaneously evaporating all the particles in a strip and
reoccupying these sites with a new appropriately chosen configuration. We
implement the algorithm for the particular case of the hard-core lattice gas in
which the first k next-nearest neighbors of a particle are excluded from being
occupied. It is shown that the algorithm is able to reproduce the known results
for k = 1,2,3 both on the square and cubic lattices. We also show that, in
comparison, the corresponding flat histogram algorithms with either local moves
or unbiased cluster moves are less accurate and do not converge as the system
size increases.
