Write a program that inputs one-character commands that instruct the program to run one of the recursive functions below. Use switch to select function. Output appropriate results. All I/O should be done in main. You must use a multi-file format. Implement your code using separate header and c++ files for the functions. I.e., all functions can declared and coded using one .h and one .cpp file. Files: main.cpp Recur_Fun.h Recur_Fun.cpp

Comments in the code should explain how your recursion works. Recursive functions to implement:

[R] str_rev returns the reverse of the argument string. Parameter is passed by reference and constant. Input the string from the console.

[P] palin returns a Boolean indicating whether or not the argument string is a palindrome. Parameter is constant passed by value. Input the string.

[F] find_sub returns a Boolean indicating if the first argument string is a substring of the second. That is, the first argument occurs anywhere in the second. E.g., "to", "day, "oda", are all substrings of "today". Also, "today" would be considered a substring of itself. Parameters are constant pass by reference. Input the substring to find followed by the string to search.

[M] list_max returns the max of a non-negative, integer vector passed by reference and may be changed by function if needed. Input the integers. End with a negative value (do not include the negative value in the list). This recursive implementation can be tricky. Some thoughts. Base case is one element in the vector. Otherwise, return the max(list(0), list_max(tail(list))). tail(list) is the list with list(0) removed. You can also do the same thing by starting at the end of the list instead of the beginning, which would be more efficient.

[E] Not a function but is the command to end the program