the flight details are stored in the form of a map<string<map>> format . after addition the details are added into this vector which is always fetched by the user
seat-matrix refers to the arrangement of seats. the user will be shown seats automatically on the basis of seat matrix since the loop is using the characters of seat matrix as i,j
#IF YOU WANT TO CONTRIBUTE YOU CAN WORK AT DELETION OF FLIGHT, NOT TO DISPLAY FLIGHTS OF THE PASSED TIME(OF THE CURRENT DAY ONLY) , SINCE I HAVE TAKEN CARE OF THE PAST DAYS HERE