  We consider a one-dimensional system of particles with strong zero-range
interactions. This system can be mapped onto a spin chain of the Heisenberg
type with exchange coefficients that depend on the external trap. In this
paper, we present an algorithm that can be used to compute these exchange
coefficients. We introduce an open source code CONAN (Coefficients of
One-dimensional N-Atom Networks) which is based on this algorithm. CONAN works
with arbitrary external potentials and we have tested its reliability for
system sizes up to around 35 particles. As illustrative examples, we consider a
harmonic trap and a box trap with a superimposed asymmetric tilted potential.
For these examples, the computation time typically scales with the number of
particles as $O(N^{3.5 \pm 0.4})$. Computation times are around 10 seconds for
$N=10$ particles and less than 10 minutes for $N=20$ particles.
