What kind of algorithm do elevators use to determine which one will take the next request?
Can you please elaborate on the phrase which one will take the next request ??
For implementing elevator or lift mechanism C-SCAN or SCAN algorithm is used.
When a new request arrives while the drive is idle, the initial arm/head movement will be in the direction of the cylinder where the data is stored, either in or out.
Both SCAN and C-SCAN behave in the same manner until they reach the last track queued. For the sake of this example let us assume that the SCAN algorithm is currently going from a lower track number to a higher track number