1 class Solution {
 2     public int wiggleMaxLength(int[] nums) {
 3         int up = 1, down = 1;
 4         if(nums.length == 0) return 0;
 5         for(int i = 0; i < nums.length - 1; i++){
 6             if(nums[i + 1] > nums[i]){
 7                 down = up + 1;
 8             }else if(nums[i + 1] < nums[i]){
 9                 up = down + 1;//注意等于的情况不算
10             }
11         }
12         return Math.max(up, down);
13     }
14 }

动态规划 很懒 拿电脑画图忽悠了 大佬思路牛逼