diff --git a/map/src/map.hpp b/map/src/map.hpp
index 4357ced..f2504e2 100644
--- a/map/src/map.hpp
+++ b/map/src/map.hpp
@@ -115,7 +115,7 @@ class map {
         return;
       }
       RedBlackTreeNodeType *uncle = GetUncle();
-      RedBlackTreeColorType *grand_parent = GetGrandParent();
+      RedBlackTreeNodeType *grand_parent = GetGrandParent();
       if (uncle != nullptr && uncle->color == RedBlackTreeColorType::RED) {
         // Case 4
         parent->color = RedBlackTreeColorType::BLACK;
@@ -157,17 +157,19 @@ class map {
      * @param val The value to be inserted.
      * @param allow_replacement Whether to allow replacement if the key already exists.
      *
-     * @return Whether the insertion is successful.
+     * @return Whether the insertion is successful and where the insertion is.
      *
      * @note Note that tree_root is a reference to the root of the tree. This function will modify the tree_root if
      * necessary.
      */
-    bool Insert(RedBlackTreeNodeType *&tree_root, const value_type &val, bool allow_replacement) {
+    std::pair<RedBlackTreeNodeType *, bool> Insert(RedBlackTreeNodeType *&tree_root, const value_type &val,
+                                                   bool allow_replacement) {
       if (comparer(val.first, this->val.first)) {
         if (left == nullptr) {
           left = new RedBlackTreeNodeType(val, nullptr, nullptr, this, RedBlackTreeColorType::RED);
           left->parent = this;
           left->InsertFixUp(tree_root);
+          return std::pair<RedBlackTreeNodeType *, bool>(left, true);
         } else {
           return left->Insert(tree_root, val, allow_replacement);
         }
@@ -176,16 +178,17 @@ class map {
           right = new RedBlackTreeNodeType(val, nullptr, nullptr, this, RedBlackTreeColorType::RED);
           right->parent = this;
           right->InsertFixUp(tree_root);
+          return std::pair<RedBlackTreeNodeType *, bool>(right, true);
         } else {
           return right->Insert(tree_root, val, allow_replacement);
         }
       } else {
         if (allow_replacement) {
-          this->val = val;
-          return true;
+          this->val.second = val.second;
+          return std::pair<RedBlackTreeNodeType *, bool>(this, false);
         }
       }
-      return false;
+      return std::pair<RedBlackTreeNodeType *, bool>(this, false);
     }
     /**
      * @brief The definition of ReleaseAll.
@@ -200,9 +203,27 @@ class map {
       delete left;
       delete right;
     }
+    RedBlackTreeNodeType *Find(const decltype(val.first) &key) {
+      if (comparer(key, val.first)) {
+        if (left == nullptr) return nullptr;
+        return left->Find(key);
+      } else if (comparer(val.first, key)) {
+        if (right == nullptr) return nullptr;
+        return right->Find(key);
+      } else {
+        return this;
+      }
+    }
   };
   size_t node_count;
   RedBlackTreeNodeType *tree_root;
+  void CopyFrom(RedBlackTreeNodeType *&target, const RedBlackTreeNodeType *source) {
+    if (source == nullptr) return;
+    target = new RedBlackTreeNodeType(source->val, nullptr, nullptr, nullptr, source->color);
+    CopyFrom(target->left, source->left);
+    CopyFrom(target->right, source->right);
+    target->SetChildrensParent();
+  }
 
  public:
   /**
@@ -222,6 +243,7 @@ class map {
     map *domain;
 
    public:
+    friend const_iterator;
     iterator() : raw_pointer(nullptr), domain(nullptr) {}
     iterator(const iterator &other) : raw_pointer(other.raw_pointer), domain(other.domain) {}
     iterator(RedBlackTreeNodeType *raw_pointer, map *domain) : raw_pointer(raw_pointer), domain(domain) {}
@@ -304,6 +326,7 @@ class map {
     const map *domain;
 
    public:
+    friend iterator;
     const_iterator() : raw_pointer(nullptr), domain(nullptr) {}
     const_iterator(const const_iterator &other) : raw_pointer(other.raw_pointer), domain(other.domain) {}
     const_iterator(const iterator &other) : raw_pointer(other.raw_pointer), domain(other.domain) {}
@@ -375,46 +398,90 @@ class map {
     value_type *operator->() const noexcept { return &raw_pointer->val; }
   };
   map() : node_count(0), tree_root(nullptr) {}
-  // TODO copy constructor
-  map(const map &other) {}
+  map(const map &other) {
+    node_count = other.node_count;
+    CopyFrom(tree_root, other.tree_root);
+  }
+  map(map &&other) {
+    node_count = other.node_count;
+    tree_root = other.tree_root;
+    other.node_count = 0;
+    other.tree_root = nullptr;
+  }
   /**
    * TODO assignment operator
    */
-  map &operator=(const map &other) {}
+  map &operator=(const map &other) {
+    if (this == &other) return *this;
+    if (tree_root) tree_root->ReleaseAll();
+    delete tree_root;
+    node_count = other.node_count;
+    CopyFrom(tree_root, other.tree_root);
+  }
+  map &operator=(map &&other) {
+    if (this == &other) return *this;
+    if (tree_root) tree_root->ReleaseAll();
+    delete tree_root;
+    node_count = other.node_count;
+    tree_root = other.tree_root;
+    other.node_count = 0;
+    other.tree_root = nullptr;
+  }
   ~map() {
     if (tree_root) tree_root->ReleaseAll();
     delete tree_root;
   }
   /**
-   * TODO
    * access specified element with bounds checking
    * Returns a reference to the mapped value of the element with key equivalent to key.
    * If no such element exists, an exception of type `index_out_of_bound'
    */
-  T &at(const Key &key) {}
-  const T &at(const Key &key) const {}
+  T &at(const Key &key) {
+    RedBlackTreeNodeType *result = tree_root->Find(key);
+    if (result == nullptr) throw index_out_of_bound();
+    return result->val.second;
+  }
+  const T &at(const Key &key) const {
+    RedBlackTreeNodeType *result = tree_root->Find(key);
+    if (result == nullptr) throw index_out_of_bound();
+    return result->val.second;
+  }
   /**
    * TODO
    * access specified element
    * Returns a reference to the value that is mapped to a key equivalent to key,
    *   performing an insertion if such key does not already exist.
    */
-  T &operator[](const Key &key) {}
+  T &operator[](const Key &key) {
+    auto result = tree_root->Insert(tree_root, value_type(key, T()), false);
+    if (result.second) ++node_count;
+    return result.first->val.second;
+  }
   /**
    * behave like at() throw index_out_of_bound if such key does not exist.
    */
-  const T &operator[](const Key &key) const {}
+  const T &operator[](const Key &key) const { return at(key); }
   /**
    * return a iterator to the beginning
    */
-  iterator begin() {}
-  const_iterator cbegin() const {}
+  iterator begin() {
+    if (tree_root == nullptr) return iterator(nullptr, this);
+    RedBlackTreeNodeType *tmp = tree_root;
+    while (tmp->left != nullptr) tmp = tmp->left;
+    return iterator(tmp, this);
+  }
+  const_iterator cbegin() const {
+    if (tree_root == nullptr) return const_iterator(nullptr, this);
+    RedBlackTreeNodeType *tmp = tree_root;
+    while (tmp->left != nullptr) tmp = tmp->left;
+    return const_iterator(tmp, this);
+  }
   /**
    * return a iterator to the end
    * in fact, it returns past-the-end.
    */
-  iterator end() {}
-  const_iterator cend() const {}
+  iterator end() { return iterator(nullptr, this); }
+  const_iterator cend() const { return const_iterator(nullptr, this); }
   /**
    * checks whether the container is empty
    * return true if empty, otherwise false.
@@ -427,7 +494,12 @@ class map {
   /**
    * clears the contents
    */
-  void clear() {}
+  void clear() {
+    if (tree_root) tree_root->ReleaseAll();
+    delete tree_root;
+    tree_root = nullptr;
+    node_count = 0;
+  }
   /**
    * insert an element.
    * return a pair, the first of the pair is
@@ -438,8 +510,11 @@ class map {
     if (tree_root == nullptr) {
       tree_root = new RedBlackTreeNodeType(value, nullptr, nullptr, nullptr, RedBlackTreeNodeType::BLACK);
       node_count = 1;
-      return pair<iterator, bool>(iterator(tree_root), true);
+      return pair<iterator, bool>(iterator(tree_root, this), true);
     }
+    auto result = tree_root->Insert(tree_root, value, false);
+    if (result.second) ++node_count;
+    return pair<iterator, bool>(iterator(result.first, this), result.second);
   }
   /**
    * erase the element at pos.
@@ -454,16 +529,28 @@ class map {
    *     since this container does not allow duplicates.
    * The default method of check the equivalence is !(a < b || b > a)
    */
-  size_t count(const Key &key) const {}
+  size_t count(const Key &key) const {
+    if (tree_root == nullptr) return 0;
+    return tree_root->Find(key) == nullptr ? 0 : 1;
+  }
   /**
    * Finds an element with key equivalent to key.
    * key value of the element to search for.
    * Iterator to an element with key equivalent to key.
    *   If no such element is found, past-the-end (see end()) iterator is returned.
    */
-  iterator find(const Key &key) {}
-  const_iterator find(const Key &key) const {}
+  iterator find(const Key &key) {
+    if (tree_root == nullptr) return end();
+    return iterator(tree_root->Find(key), this);
+  }
+  const_iterator find(const Key &key) const {
+    if (tree_root == nullptr) return cend();
+    return const_iterator(tree_root->Find(key), this);
+  }
 };
+// Define the static member comparer.
+template <class Key, class T, class Compare>
+Compare map<Key, T, Compare>::comparer = Compare();
 
 }  // namespace sjtu