problem 1) Assume you are given a timetable, that consists of:

(a) set A of n airports, and for each airport a in A, a minimum connecting time c(a).

(b) set F of m flights, and for each flight f in F, the following information:

i) origin airport a1(f) in A;

ii) destination airport a2(f) in A;

iii) departure time t1(f); and

iv) arrival time t2(f)

Give the efficient algorithm for the following problem:

Given airports a and b, and time t, determine the sequence of flights which allows one to arrive at the earliest possible time in b when departing from a at or after time t. Minimum connecting times at intermediate airports must be assumed. Also, give time complexity of your algorithm as the function of n and m. The program must check that number of credits is a positive number and that valid letter grade is entered. In either case, the program must prompt the user until valid data has been entered.