Flight-scheduler

• The subject of the project is to create a lightweight flight planner that computes the least priced trip between two cities in a given period of time.
• The input is the set of flights between various cities. It is given as a file. Each line of the file contains an input of the format: City1 | City2 | Departure-time | Arrival-time | Flight-no. | Price which means that there is a flight called 'flight-no' (which is a string of the form XY012) from city1 to city2 which leaves city1 at time 'departure-time' and arrives city2 at time 'arrival-time'.
• Further the price of this flight is "price" which is a positive integer. All times are represented as a string of 4 digits in the 24hr format e.g. 1135, 0245, 2210.
• It is assumed that all city names are integers between 1 and a number N (where N is the total number of cities). There can be multiple flights between two cities (at different times).
• A customer can make an enquiry as follows: given two cities 'A' and 'B', times 't1', 't2', where t1 < t2, find the cheapest trip which leaves city 'A' after time 't1' and arrives at city 'B' before time 't2'. A trip is a sequence of flights which starts at A after time t1 and ends at B before time t2. If no such sequence is possible, it conveys such to the customer.
• Further, the departure time from any transit (intermediate) city C is at least 30 mins after the arrival at C.