Write a fully modular C program that reads in a string of a defined size from the keyboard and reports how many times each letter of the alphabet occurs within that string (ignoring case). It should also report how many non-letters are included in the string.
write a fully modular C program that reads a string of a defined maximum length from the keyboard. This input should have the ROT13 process applied to it and then output the result. Note that this process should maintain capitalisation differences and retain all non-alphabetic characters unmodified. After outputting the result, the program should ask the user if they wish to input another value and, if so, repeat the process.
Hint: the ability of the modulus operator to limit a value to within a fixed range may be useful in solving this problem.