Fibonacci数列的递归和非递归

int Fibonacci(int n)
{
if (n == 0 || n == 1)
return 1;
else
return Fibonacci(n - 1) + Fibonacci(n - 2);
}

int Fibonacci2(int n)
{
int fib1=1, fib2=1, fib3;
if (n==0||n==1)
{
return 1;
}
else
{
for (int i = 2; i <= n; i++)
{
fib3 = fib1 + fib2;
fib1 = fib2;
fib2 = fib3;
}
return fib3;
}
}