Homework #4

Problem 1:

XYZ Air is building its record-keeping data base, which
can be pictured hierarchically as follows:

                         XYZ Air

              /             |           \

        Flight 1         Flight 2   ...    Flight N   

        /     \          /     \           /      \

    Jan 1...Jan 31   Jan 1...Jan 31      Jan 1...Jan 31

  /  |  \                               /  |  \

Ani Bob...Zen                        Cary Dave...Sam


As seen on the picture, the first level of this tree represents
a list of flights ordered by number, the second level represents 
ordered lists of days, and the third level represents ordered
list of passengeres for each day of each flight.

Write a program to maintain this data base. Your program should 
process requests to add, delete and list the following:

   -  Specified flight number.
   -  For a given flight number, specified day of the month.
   -  For a given flight number and day of the month, specified
      passenger or all passengers.


Problem 2: (This is not a programming project) Assume that
keys arrive for insertion in an initially empty 2-3 tree in 
the following order: 100, 90, 80, 70, 60, 50, 40, 30, 20, 10. 
Build the resulting tree showing each step of the insertion
process. Define the percentage of information fields wasted 
by storing empty flags in the final tree.