class Solution {
public:
int wiggleMaxLength(vector<int>& nums) {
nums.erase(unique(nums.begin(),nums.end()),nums.end());
if(nums.size()<=2)return nums.size();
int count=2;
for(int i=1;i+1<nums.size();i++)
{
int a=nums[i-1],b=nums[i],c=nums[i+1];
if(a<b&&b>c)count++;
else if(a>b&&b<c)count++;
}
return count;
}
};