Recursive to iteration

[Tongie]

Hi, I need some help on this. I need to convert the recursive version to iteration version using while loop but I just cant get it right. There is something wrong with my iteration version..Thanks you alot!

#include <iostream>
using namespace std;

int recusion(int);
int iteration(int);


int main ()
{
	int n;

	cout << "Enter a integers: ";
	cin >> n;

	cout << recusion(n);
	cout << endl;
	cout << iteration(n);
	cout << endl;
	
}

int recusion(int n)
{
	if(n == 1)
		return 3;
	else if(n == 2)
		return 2;
	else			
		return recusion(n - 2) + recusion(n - 1);
}

int iteration(int n)
{
	int pCur = 0;
	int pNext = 0;
	int pOld = 0;
	int i = 1;
	
	while(i <= n)
	{
		if(i == 1)
		{
			pNext += 3;
			pCur = 3;
			if (n == 1)
				return pCur;
		}
		else if(i == 2)
		{
			pNext += 2; 
			pCur = 2;
			if (n == 2)
				return pCur;
		}	 
		else
			pNext = pCur + pOld;
		
		pOld = pCur;
		pCur = pNext; 
		
		i++;
	}
	return pNext;
}

[ne555]

[code]Your code goes here.[/code]
In the iterative version you are calculating one number ahead, so the loop should end early. You may want to change the handling of the special cases.