One-way flight trip problem

Question

You are going on a one-way indirect flight trip that includes billions an unknown very large number of transfers.

• You are not stoppi

Answer 1

Construct a hashtable and add each airport into the hash table.

=

Count for the airport increases if the airport is either the source or the destination. So for every airport the count will be 2 ( 1 for src and 1 for dst) except for the source and the destination of your trip which will have the count as 1.

You need to look at each ticket at least once. So complexity is O(n).