题解 | #最长无重复子数组#

public:
    /**
     * 
     * @param arr int整型vector the array
     * @return int整型
     */
    int maxLength(vector<int>& arr) {
        // write code here
        int n=arr.size();
        if(n<=1){
            return n;
        }
        int maxLength=INT_MIN;
        unordered_set<int> m_set;
        int left=0,right=0;
        while(right<arr.size()){  
            if(m_set.find(arr[right])==m_set.end()){
                m_set.emplace(arr[right]);
                right++;
            }else{
                while(m_set.find(arr[right])!=m_set.end()){
                    m_set.erase(arr[left]);
                    left++;
                }
                m_set.emplace(arr[right]);
                right++;
            }
            maxLength=max(maxLength,right-left);
        }
        return maxLength;
    }
};