private boolean calculate(final Set<Territory> startSet, final Territory end) {
final Set<Territory> nextSet = new HashSet<Territory>();
for (final Territory t : startSet) {
final Set<Territory> neighbors = m_map.getNeighbors(t, m_condition);
for (final Territory neighbor : neighbors) {
if (!m_previous.containsKey(neighbor)) {
m_previous.put(neighbor, t);
if (neighbor.equals(end)) {
return true;
}
nextSet.add(neighbor);
}
}
}
if (nextSet.isEmpty()) {
return false;
}
return calculate(nextSet, end);
}
