斐波那契数列(递归与迭代)

斐波那契数列
1 1 2 3 5 8 13 21 34 55

递归

int Fib(int n)
{
   if (n <= 2)
   {
   	return 1;
   }
   else
   	return Fib(n - 1) + Fib(n - 2);

}
int main()
{
   int n = 0;
   int ret = 0;
   scanf("%d", &n);
   //TDD-测试驱动开发
   ret = Fib(n);
   printf("ret = %d\n", ret);
   return 0;
}

迭代

int Fib(int n)
{
	int a = 1, b = 1, c = 1;
	while (n > 2)
	{
		 c = a+b;
		 a = b;
		 b = c;
		n--;
	}
	return c;

}
int main()
{
	int n = 0;
	int ret = 0;
	scanf("%d", &n);
	//TDD-测试驱动开发
	ret = Fib(n);
	printf("ret = %d\n", ret);
	return 0;
}