模仿ACwing上的查找最长不重复子串的写法,简易哈希
class Solution { public: int maxLength(vector<int>& arr) { if(arr.size() <= 1) return arr.size(); int used[100010] = {0}; int ans = 0; for(int i = 0,j = 0;i < arr.size();i++) { used[arr[i]]++; while(j < i && used[arr[i]] > 1) used[arr[j++]]--; ans = max(ans,i - j + 1); } return ans; } };