Caesar Cipher

This C++ program implements a Caesar cipher to encrypt text. It reads text from an input file, applies the cipher, and then writes the encrypted text to an output file.

Here's a brief overview of its features:

• Shift Value: The user is prompted to enter a numerical shift value. If 0 is entered, the program defaults to a shift of 3.
• File Handling: The program attempts to open C:\input.txt for reading and C:\output.txt for writing. It includes error handling to notify the user if either file cannot be opened.
• Encryption Logic: It reads up to 8000 characters from the input file. Each alphabetic character (both lowercase and uppercase) is then shifted by the specified shift_value within its respective case, wrapping around the alphabet.
• Output: The original text from the input file and the encrypted text are both printed to the console. The encrypted text is also written to the output.txt file.
• File Closure: Finally, both the input and output files are closed.