src/main/java/com/fishercoder/solutions/_2085.java

package com.fishercoder.solutions;

import java.util.HashMap;
import java.util.Map;

public class _2085 {
    public static class Solution1 {
        public int countWords(String[] words1, String[] words2) {
            Map<String, Integer> map1 = new HashMap<>();
            Map<String, Integer> map2 = new HashMap<>();
            for (String word : words1) {
                map1.put(word, map1.getOrDefault(word, 0) + 1);
            }
            for (String word : words2) {
                map2.put(word, map2.getOrDefault(word, 0) + 1);
            }
            int ans = 0;
            for (String key : map1.keySet()) {
                if (map1.get(key) == 1 && map2.containsKey(key) && map2.get(key) == 1) {
                    ans++;
                }
            }
            return ans;
        }
    }
}