_929.java

package com.fishercoder.solutions;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

public class _929 {
    public static class Solution1 {
        public int numUniqueEmails(String[] emails) {
            Map<String, Set<String>> map = new HashMap<>();
            for (String email : emails) {
                String[] parts = email.split("@");
                if (!map.containsKey(parts[1])) {
                    map.put(parts[1], new HashSet<>());
                }
                String filteredLocalName = parts[0].substring(0, parts[0].indexOf('+'));
                filteredLocalName = filteredLocalName.replace(".", "");
                map.get(parts[1]).add(filteredLocalName);
            }
            return map.keySet().stream().mapToInt(key -> map.get(key).size()).sum();
        }
    }
}