Write a program in C++ that:

1. accepts an unlimited number of strings (none of which will contain spaces)
   typed by the user

2. adds those strings, as they are typed, into an initially empty binary tree

     The order of the tree is alphabetical, and case INsensitive, so cat and CAT
     are the same string, and ant comes before Zebra.

3. when the user signals that the data entry phase is over, the program must then
   accept another unlimited sequence of strings from the user

4. when each string is typed, the program searches the tree for it, and prints
   "yes" if it is present, or "no" if it isn't.

I hope this is the same as I described it in class.