Imagine we have to park with a five parking space. When the parking space is full, newly arrived car can park after car from parking space will leave the parking.
Imagine we have car racing before we can begin, following conditions should meet:
- All five cars should be on start line
- The command "Prepare!" should be done
- The command "Ready!" should be done
- The command "Go!" should be done
It's essential that all five cars start at the same time.
Imagine we have a ferry that transport cars. The boat can transport only three vehicles at the same time, and we can carry cars just after on a ferry we had three vehicles.
Imagine we have two tracks. The first one is going from A to D, and the second one is going from B to C. The roads AD and BC is crossing at E. From A and B we should dispatch envelopes to C and D, to do that, two tracks should meet at E and exchange envelopes.
Imagine we have five bus stops. At the first four people can wait for a bus. The bus starts a journey and stops on all the bus stops, after fifth bus stop it's going to bus depot. We should:
- pick the people
- drop off the people
