Recursive Descent Parsing

Consider the following BNF grammar:

E -> P O P | P O -> + | - | * | / | ** P -> I | L | UI | UL | (E) U -> + | - | ! I -> C | CI C -> a | b | ... | y | z L -> D | DL D -> 0 | 1 | ... | 8 | 9 

Using the technique described in class implement a recursive descent parser that recognizes strings in this language. Input should be from a file called input.txt and output should be to the console. An example session might look like this (these strings are not necessarily in the language):

The string "a=a+b-c*d" is in the language. The string "a=a//b++c" is not in the language. 

You must implement the project in BOTH Java and C++! Implementations that do not include a solution in both languages will, at best, receive half credit. To simplify things you will not have to handle whitespace when parsing the string, i.e. " " and similiar are illegal characters in this language. All strings should read from a file called "input.txt" and written to a file called "output.txt".