Thread: recursive function

I am writing a recursive function that seems to work, but I have to also include a while loop to ask the user for the depth of the recursion. This is resulting in an endless loop.

Here is the code:

Code:

 void recurse(int count, int depth);	//	function prototype

 int main()
 {

	 int depth;
	 cout << "Please enter a number for recursion depth, or -1 to exit: " << endl;
	 cin >> depth;
	 while (depth != depth *2)
	 {
		 for (int counter = depth -(depth * 2); counter <= depth; counter++)
	 	 {
				recurse(counter, depth);
		 }

	cout << "Please enter a number for recursion depth, or -1 to exit: " << endl;
}
	return 0;

	 }


void recurse(int count, int depth)
{
	if (count < 0)
		cout << "This was written by call number " << (count * -1) << "." << endl;
	else if (count > 0)
		cout << "This was ALSO written by call number " << count << "." << endl;
	else if (count == depth)
		return;
}

Any ideas on how to break from this while loop?

If you're just interested in a recursive call x number of times, then a while loop is not needed. Just pass an argument that gets decremented by 1 in each recursion.

Code:

void Recurse(int Count)
{
   if(Count > 0) Recurse(Count - 1);
}

void StartRecursion()
{
   cin >> NrOfTimes;
   Recurse(NrOfTimes);
}

My program needs to print out something similar to this:

Get input from user for incursion depth of x = 5, so:

This was written by call number x.
This was written by call number x-1.
This was written by call number x-2.
This was written by call number x-3.
This was written by call number x-.4
This was ALSO written by call number x-4.
This was ALSO written by call number x-3.
This was ALSO written by call number x-2.
This was ALSO written by call number x-1.

My question is how to construct my while loop to prompt the user for another incursion depth, or a sentinel to exit.

I don't know what a sentinel is...
You could use 0 as an exit condition though:

Code:

int InputDepth;

while(true)
{
   cin >> InputDepth;
   if(InputDepth == 0) break;
   Recurse(InputDepth);
}

perfect! thanks Magos