C++ Solution
Approach\n Describe your approach to solving the problem. \n    Map\n\n# Complexity\n- Time complexity:\n Add your time complexity here, e.g. O(n) \n    O(N)\n\
# Approach\n<!-- Describe your approach to solving the problem. -->\n    Map\n\n# Complexity\n- Time complexity:\n<!-- Add your time complexity here, e.g. $$O(n)$$ -->\n    O(N)\n\n- Space complexity:\n<!-- Add your space complexity here, e.g. $$O(n)$$ -->\n    O(N)\n\n# Code\n```\nclass Solution {\npublic:\n    int numUniqueEmails(vector<string>& emails) {\n        unordered_map<string, int> mp;\n        for(auto x: emails) {\n            bool fl = 1, at = 0;\n            string s;\n            for(auto c: x) {\n                if(!at && c == \'.\') continue;\n                else if(!at && c == \'+\') fl = 0;\n                else if(c == \'@\') at = 1, fl = 1, s.push_back(c);\n                else if(fl) s.push_back(c);\n            }\n            mp[s]++;\n        }\n        return mp.size();\n    }\n};\n```
['C++']