The problem statement is like this --
There are list of passengers who have been given PNR numbers for their itinerary of travel and their tickets have been booked using blockchain technology. If their travels are can-celled or delayed they are given HOTEL ACCOMMODATION through the TRAVEL PORT application by the booking agency.
An individual passenger having a PNR can also book a HOTEL ACCOMMODATION through TRAVEL PORT using an application.
If the HOTEL ACCOMMODATION booking happens through both ways – one by booking agency and another by passenger itself by going to the application portal.
How can uniqueness of PNR can be checked so that only single HOTEL ACCOMMODATION is given?