代碼：

class Solution {
public:int totalFruit(vector<int>& fruits) {int n = fruits.size();unordered_map<int,int> window_type_count;int left = 0;int ans = 0;for(int right = 0; right <n;right++){while(window_type_count.size() ==2 && !window_type_count.contains(fruits[right])){window_type_count[fruits[left]]--;if(window_type_count[fruits[left]] == 0){window_type_count.erase(fruits[left]);}left++;}if(window_type_count.contains(fruits[right]))window_type_count[fruits[right]]++;elsewindow_type_count[fruits[right]] = 1;// if(window_type_count.size()==2){ans = max(ans,right-left+1);// }}return ans;}
};