【算法】斐波那契（Fibonacci ）数列第N项

一、

int fib2(int n)
{
	if(n == 0)
	  return 0;
	if(n == 1)
	  return 1;
	return fib2(n-1)+fib2(n-2);
}

二、、

int fib(int n)
{
	int result[2] = {0,1};
	if(n < 2)
		return result[n];
	int fibOne = 0;
	int fibTwo = 1;
	int fibN   = 0;
	int i = 0;
	for(i = 2; i <= n; i++)
	{
		fibN = fibOne + fibTwo;
		
		fibOne = fibTwo;
		fibTwo = fibN;
	}
	
	return fibN;
}