java - 我怎样才能把这个递归方法变成迭代方法？

Question

我需要制作 Raju()使用for循环的方法我怎么做？

public class Fall2012COP3337MidtermRecursion 
{
    // trace recursion
    public static void main(String[] args) 
    {        
        System.out.println("Raju(6) = " + Raju(6));        
    }

    // compute the nth Raju number
    private static long Raju(int n)
    {        
        if (n < 0)
           return 0L;
        if (n == 0 || n == 1)
           return 1L;

        return Raju(n-1) + Raju(n-2) + 1; // recurse
    }
}

Answer 1

private static long Raju_Iterative(int n)
{        
    if (n < 0)
        return 0L;
    long a = 1L;
    long b = 1L;
    for(int i = 0; i < n-1; i++) {
        long c = a+b+1;
        a = b;
        b = c;
    }
    return b;
}