LeetCode-929._Unique_Email_Addresses_via_CPP/main.cpp

#include <unordered_set>
#include <string>
#include <vector>

class Solution {
public:
    int numUniqueEmails(std::vector<std::string>& emails) {
        std::unordered_set<std::string> uniqueEmails;
        for (const auto& email : emails) {
            int atPos = email.find('@');
            std::string local = email.substr(0, atPos);
            std::string domain = email.substr(atPos);
            local.erase(std::remove(local.begin(), local.end(), '.'), local.end()); // Remove '.' characters in the local part
            local = local.substr(0, local.find('+')); // Remove everything after the first '+' in the local part
            uniqueEmails.insert(local + domain); // Combine back to form the unique email
        }
        return uniqueEmails.size();
    }
};