Write a c program to encrypt and decrypt a string using Caesar Cipher method

Main program

Input will be a string and a key.

Call encrypt function and pass the required parameters

Call decrypt function and pass the required parameters.

Encrypt Function

Use for loop to take the characters one by one until the end of the string.

Check if the letter is uppercase, If it is true, use x=(x-'A' + key) % 26 +'A'

Else use x=(x-'a' + key) % 26 +'a'

Decrypt Function

Use for loop to take the characters one by one until the end of the string.

Check if the letter is uppercase, If it is true, use x=(x-'A' - key) % 26 +'A'

Else use x=(x-'a' - key) % 26 +'a'