题解 | #最长无重复子数组#

class Solution {
public:
    /**
     * 
     * @param arr int整型vector the array
     * @return int整型
     */
    int maxLength(vector<int>& arr) {
        // write code here
        if(arr.size()==0)return 0;
        if(arr.size()==1)return 1;
        int max = 0;
        int sum = 0;
        unordered_map<int, int> map;
        for(int i = 0; i < arr.size(); i++){
            if(!map.empty() && map.find(arr[i]) != map.end()){
                if(sum > max)max = sum;
                i = map[arr[i]] + 1;
                map.clear();
                map[arr[i]] = i;
                sum = 1;
            }else{
                map[arr[i]] = i;
                sum++;
            }
        }
        max = max>sum?max:sum;
        return max;
    }
};