Write a program to solve a simple class of
cryptarithmetic problems MORE EFFICIENTLY THAN BY BRUTE FORCE (EXHAUSTIVE
SEARCH) by using deductions about even/odd, digit range, etc.  For example, in 
the test case 

 CADET
+CORPS
------
 TROOP

given below your program can deduce that C<5.  (You do not have to use this 
deduction; this is just an example of a deduction which would reduce the search
space.) By convention, each letter stands for a different digit and there are
no leading zeroes.

You program should read strings (hint: in C, use fgets), right justify the 
strings to make an addition problem, and find a solution.  If there is more 
than one solution, you only need to find one.  For the example in Figure 5.2, 
the input would be

 TWO
 TWO
FOUR

Run your program on this example plus the following:

JAVA
 OOP
LANG

CADET
CORPS
TROOP

 KYLE 
FIELD
AGGIE

The grader will also run your project on additional problems.  You may assume
the input contains only upper case letters, and no more than 10 different 
letters.