Recursion program

[Shannon Holder]

Thank you, Shinigami. I guess I don't understand recursion as well as I thought.
My prof requested that the reverseDisplay function user a helper function so I am trying to do it this way.

[Shinigami]

???
for what purpose to use a helper function :/

you are learning recursion, are you not?
Then here are no need for helper function. Or are you learning how to use function from another function :)

And I don't know why you use &s if you don't change a given string.

Are you sure that your teachers are trained in computer programming? :D

[Shannon Holder]

Prof says:
"use helper function to pass the substring high index to the function. The helper function header is:

void reverseDisplay (const string &s, int high)

recursive function header is:

reverseDisplay(const string&s)"

This is the assigment...

[Shinigami]

well you can use a helper function and it still will be 3 line, but two functions.

[Shinigami]

If you need a helper function, here it is.

void reverseDisplay(string s)
{
	int simbol = s.length() - 1;
	reverseDisplay(s, simbol);
}

void reverseDisplay(string s, int simbol)
{
	cout << s[simbol];
	if (simbol)
		reverseDisplay(s, simbol - 1);
}

but I would use this function, one function

void reverseDisplay(string s)  //reverse display function
{
	cout << s[s.length() - 1];
	if (!s.empty())
		reverseDisplay(s.substr(0, s.length() - 1));
}

[Shannon Holder]

Yes, I had to change a few things in the code, but it works. I thank you... I will study this second code you sent as it looks easier.

[Shinigami]

In this two examples firs example may by a little faster if you have string over 100000 length, as it don't need to recount string length. But you can modify second example to do the same.

void reverseDisplay(string s, int simbol)  //reverse display function
{
	cout << s[simbol];
	if (simbol)
		reverseDisplay(s, simbol - 1);
}

and call it
reverseDisplay(sreverse, sreverse.length() - 1); //sends string to function for reversing