def assign_lift(route, buses, picked_up):
new_route = Route()
for stop_ind, stop in enumerate(route.stops):
if picked_up[stop_ind]:
continue
#If this is a wheelchair stop, see whether we can add it to the route
if stop.count_needs("W") > 0 or stop.count_needs("L") > 0:
new_route.add_stop(stop)
picked_up[stop_ind] = True
possible = False
for bus in buses:
if bus.route == None and bus.lift and bus.can_handle(
new_route):
possible = True
break
if not possible:
new_route.remove_stop(stop)
picked_up[stop_ind] = False
#Now as many wheelchair students as can fit on one
#bus have been picked up. Add other students if possible
for stop_ind, stop in enumerate(route.stops):
if picked_up[stop_ind]:
continue
if stop.count_needs("W") == 0 and stop.count_needs("L") == 0:
if not new_route.add_stop(stop):
continue
picked_up[stop_ind] = True
possible = False
for bus in buses:
if bus.route == None and bus.lift and bus.can_handle(
new_route):
possible = True
break
if not possible:
new_route.remove_stop(stop)
picked_up[stop_ind] = False
for bus in buses:
if bus.lift and bus.can_handle(new_route):
assert bus.assign(new_route)
break
#Keep stops in the same order. This ensures that the travel time
#doesn't increase, violating regulations.
new_route.stops.sort(key=lambda s: route.stops.index(s))
new_route.recompute_length()
buses.remove(new_route.bus)
#If we failed to pick up all wheelchair students,
#need to continue assigning wheelchair buses.
recursive_routes = []
for stop_ind, stop in enumerate(route.stops):
if (not picked_up[stop_ind]
and (stop.count_needs("W") > 0 or stop.count_needs("L") > 0)):
recursive_routes = assign_lift(route, buses, picked_up)
recursive_routes.append(new_route)
assert new_route.feasibility_check(verbose=True)
return recursive_routes
