//滑动窗口,用哈希表记录当前窗口出现的字符,有重复字符出现时,缩小窗口(即增大窗口左边界),直至无重复 class Solution { public: int maxLength(vector<int>& arr) { int n=arr.size(); unordered_set<int> mark; int ans=0; int left=0; int right=0; for(;right<n;++right) { if(mark.count(arr[right])) { ans=max(ans,right-left); while(left&l...