斐波那契 非递归方法

#include <iostream>

using namespace std;


int Fib(int n)
{
	if(n == 0 || n == 1)
	{
		return n;
	}
	int pPrev = 0;
	int prev = 1;
	int res = 0;
	for(int i = 2; i <= n; i++)
	{
		 res = prev + pPrev;
		 pPrev = prev;
		 prev = res;
	}
	return res;
}

int main()
{
	int sum = Fib(4);
}