376. 摆动序列

求取所有的差值保存起来。然后再判断一正一负的规律是否成立

var flag int
func wiggleMaxLength(nums []int) int {if len(nums) < 1 {return 0}if len(nums) == 1 {return 1}var res intresult := make([]int,len(nums))m := 0for i:=0; i<len(nums)-1; i++ {if nums[i] != nums[i+1] {result[m] = nums[i] - nums[i+1]m++}}if result[0] < 0 {flag = -1} else {flag = 1}for i:=0; i<len(result); i++ {if flag * result[i] > 0 {flag *= -1res += 1}}return res + 1
}