斐波那契数列第N位的值（N从0开始）-基于Go

• 递归

func fibRecursive(n int)int{
	if n==0{
		return 0
	}
	if n==1{
		return 1
	}

	return fibRecursive(n-1) + fibRecursive(n-2)
}

• 动态规划

func fibDynamic(n int)int{
	var arr = []int{0,1}
	for i:=2;i<=n;i++{
		arr = append(arr, arr[i-1]+arr[i-2])
	}

	return arr[n]
}

• 动态规划（空间改进）

func fibDynamic2(n int)int{
	var arr = []int{0,1}
	var tmp int
	for i:=2;i<=n;i++{
		tmp = arr[1]
		arr[1] = arr[0]+arr[1]
		arr[0] = tmp
	}

	return arr[1]
}

• 双指针

func fibDoublePointer(n int)int{
	var low = 0
	var high = 1

	for i:=2;i<=n;i++{
		sum := low+high
		low = high
		high = sum
	}
	return high
}