Got this question as part of Machine Coding Round to design a toll management system.

Requirement:

• There are multiple tolls across country and each toll has several booths
• A Vehicle can be issued 3 type of passes:
  • Single Day Pass (Can be used only once)
  • Return Pass (Can be used for return journey on same day)
  • Seven Day Pass (Can be used as many number of times during 7 days duration)
• There are two type of vehicles - 2 wheeler and 4 wheeler

Assumptions

• Toll and toll booths creation APIs are already available
• Pricing varies as per the vehicle type but is independent of the route
• No need to implement database
• Vehicle is identified by its registration number

Demonstrations

• If a vehicle has a valid pass, let it through
• If a vehicle has an invalid pass, display 3 options for passes with prices and let the user choose one and issue the pass
• Display leaderboard for each both for sales made in last 1 hour.