Solved: 27 - Unordered Containers

modules/07_stl_containers/src/unordered_containers.cpp

@@ -1,21 +1,37 @@
 #include "unordered_containers.hpp"
 
+#include <algorithm>
+#include <set>
+
 namespace stl_containers {
 
 auto first_unique(const std::vector<std::string>& words) -> std::string {
-    (void)words;
-    return {};
+    auto s = std::set<std::string>();
+    for (const auto& word : words) {
+        if (!s.contains(word)) {
+            s.insert(word);
+        } else {
+            s.erase(word);
+        }
+    }
+    return s.empty() ? "" : *s.begin();
 }
 
 auto group_anagrams(const std::vector<std::string>& words)
     -> std::unordered_map<std::string, std::vector<std::string>> {
-    (void)words;
-    return {};
+    auto groups = std::unordered_map<std::string, std::vector<std::string>>();
+    for (const auto& word : words) {
+        auto key = word;
+        std::ranges::sort(key);
+        groups[key].push_back(word);
+    }
+    return groups;
 }
 
 auto has_duplicate(const std::vector<int>& data) -> bool {
-    (void)data;
-    return false;
+    auto s = std::set<int>{};
+    for (auto i : data) s.insert(i);
+    return s.size() != data.size();
 }
 
 }  // namespace stl_containers