Stair-Case problem- Cracking the coding Interview.

#include "stdafx.h"
#include "iostream"
using namespace std;

class Solution{
public:
	int count(int n) {
		if (n<0)
			return 0;
		if (!n)
			return 1;

		return count(n - 1)+count(n - 2)+count(n - 3);
	}
};
int main()
{
	Solution s;
	cout<<s.count(5);
    return 0;
}