(Operating System) The traffic of a bridge is shown in the following diagram.
The road has north bound traffic and south bound traffic at the same time, but the bridge can only have one direction to pass at a time (multiple same direction cars is fine). Use semaphore to write a synchronization algorithm so that the traffic can pass through the bridge normally.
The solution doesn't have to be starvation-free, but if there is starvation problem, explain why your solution might cause starvation.