An ordinary text file called StolenNumbers.txt contains a lot of stolen 
credit card numbers. Each line is exactly 57 characters long (including 
the \n at the end), formatted thus: 20 characters for the owner's last 
name, 20 characters for their first name, and 16 characters for the credit 
card number. Here are just a few examples from the file:

Ampersand           Gregorina           5465874526370945
Anderson            Bob                 4235838387422002
Anderson            Petunia             4235473838457294
Aphid               Bumbellina          8392489357392473
Armstrong-Jones     Mike                8238742438632892

Typical files have very very many such lines.
As you may have noticed, the lines are always in alphabetical order.

Give a C++ implementation of a binary chop search on the file.

Do not read all of the file into memory. Only read one line at a time, 
and only read the lines necessary to perform a binary chop search. (So, 
for example, if the file has 1023 lines, you should read no more than 
10 lines for each search performed).

You should implement this as a class that keeps the open file in a member 
so that it does not need to reopen the file again (or recompute any other 
information) for each search performed.

Your search method should have two parameters giving the last and first 
names of the card owner, and return the card number as a string if it is 
found.

Example:
	CardSearch cs("StolenNumbers.txt");
	string s = cs.find("Anderson", "Bob");
	// s is now "4235838387422002"