C++ 递归/非递归实现斐波那契数列 Golang 闭包实现斐波那契数列

C++ 递归

int Fibonacci(int n)
{
	if(n==1||n==2) //1和2不用计算直接返回1
	return 1;
	return Fibonacci(n-1)+Fibonacci(n-2);
}

C++ 非递归

int Fibonacci2(int n)
{
	if(n==1||n==2) return 1;
	int fn1	=	1;
	int fn2 =	1;
	int fn;
	for(int i = 3;i <= n; i++)
	{
	     fn = fn1+ fn2;
	     fn2 = fn1;
	     fn1 = fn;
	}
	return fn;
}

Golang闭包实现

func Fibonacci3() func int{
   back1,back2 := 0,1
   return func int{
   back1,back2 = back2, (back1+back2)
   return back1
}