2053. Kth Distinct String in an Array

class Solution {
public:
    string kthDistinct(vector<string>& arr, int k)
    {
        unordered_map<string, int> m;
        for (const auto& str : arr) m[str]++;
        for (const auto& num : arr)
        {
            if (m[num] == 1 && !--k) return num;
        }
        return "";
    }
};

• T: $O(N)$
• S: $O(N)$