884 - Uncommon Words from Two Sentences

 JS

var uncommonFromSentences = function (s1, s2) {
    const cnt = new Map();
    for (const s of [...s1.split(' '), ...s2.split(' ')]) {
        cnt.set(s, (cnt.get(s) || 0) + 1);
    }
    const ans = [];
    for (const [s, v] of cnt.entries()) {
        if (v == 1) {
            ans.push(s);
        }
    }
    return ans;
};

C++

• class Solution {
  public:
      vector<string> uncommonFromSentences(string s1, string s2) {
          unordered_map<string, int> cnt;
          auto add = [&](string& s) {
              stringstream ss(s);
              string w;
              while (ss >> w) ++cnt[move(w)];
          };
          add(s1);
          add(s2);
          vector<string> ans;
          for (auto& [s, v] : cnt)
              if (v == 1) ans.emplace_back(s);
          return ans;
      }
  };

JAVA

• class Solution {
      public String[] uncommonFromSentences(String s1, String s2) {
          Map<String, Integer> cnt = new HashMap<>();
          for (String s : s1.split(" ")) {
              cnt.put(s, cnt.getOrDefault(s, 0) + 1);
          }
          for (String s : s2.split(" ")) {
              cnt.put(s, cnt.getOrDefault(s, 0) + 1);
          }
          List<String> ans = new ArrayList<>();
          for (var e : cnt.entrySet()) {
              if (e.getValue() == 1) {
                  ans.add(e.getKey());
              }
          }
          return ans.toArray(new String[0]);
      }
  }