Sorting Diverter Line

Send parcels down a belt past a row of diverter gates and report where each one ends up.

gates[i] = [dest, capacity] is the (i+1)-th gate, in belt order. Each gate has a chute that starts empty and holds at most capacity parcels. A gate's dest is a destination code, or ?, which matches every destination.

items is the stream on the belt, one item per slot, numbered from 1. An item is either a parcel (its destination code) or "*", a truck. A truck empties every chute at once and sends nothing down the belt, but it still uses up its slot.

A parcel in slot t passes the gates in order and is diverted by the first gate that is ready for it. A gate is ready when all of these hold:

• its dest equals the parcel's destination, or is ?;
• its chute is not full;
• it is not resting: after a gate diverts a parcel in slot s it rests through the next cooldown slots, so it can divert again from slot s + cooldown + 1 on. (Passing a parcel by does not make a gate rest; with cooldown = 0 a gate never rests.)

If no gate is ready the parcel reaches the end of the belt and goes into the overflow bin.

Input: gates, cooldown, items.

Output: [results, loads]. results has one number per parcel, in belt order (trucks are not listed): the 1-based number of the gate that diverted it, or 0 for the overflow bin. loads has the number of parcels in each gate's chute after the last item.