Leetcode 904. Fruit Into Baskets
sliding window(滑动窗口)算法
class Solution(object): def totalFruit(self, tree): """ :type tree: List[int] :rtype: int """ count=collections.Counter() left=ans=0 for i,val in enumerate(tree): count[val]+=1 while (len(count)>=3): count[tree[left]]-=1 if count[tree[left]]==0: del count[tree[left]] left+=1 ans=max(ans,i-left+1) return ans