#include <iostream>

using namespace std;

template<typename T>
class Set {

public:

    struct Node {
        T value;
        Node* left;
        Node* right;
        Node* parent;
    };

    Set() : root_(nullptr), size_(0) {}

    Set(const initializer_list<T>& list) : root_(nullptr), size_(0) {
        for (const T& element : list) {
            insert(element);
        }
    }

    Set(const Set& other) : root_(copy(other.root_, nullptr)), size_(other.size_) {}

    Set(Set&& other) : root_(other.root_), size_(other.size_) {
        other.root_ = nullptr;
    }

    Set& operator=(const Set& other) {
        if (this != &other) {
            clear();
            size_ = other.size_;
            root_ = copy(other.root_, nullptr);
        }
        return *this;
    }

    Set& operator=(Set&& other) {
        if (this != &other) {
            clear();
            size_ = other.size_;
            root_ = other.root_;
            other.root_ = nullptr;
        }
        return *this;
    }

    void insert(const T& val) {
        if (root_ == nullptr) {
            root_ = new Node{ val, nullptr, nullptr, nullptr };
            size_++;
            return;
        }
        Node* parent = nullptr;
        Node* node = root_;
        while (node != nullptr && node->value != val) {
            parent = node;
            node = node->value > val ? node->left : node->right;
        }
        if (node == nullptr) {
            node = new Node{ val, nullptr, nullptr, parent };
            parent->value > val ? parent->left = node : parent->right = node;
            size_++;
        }
    }

    void erase(const T& val) {
        Node* parent = nullptr;
        Node* node = root_;
        while (node != nullptr && node->value != val) {
            parent = node;
            node = node->value > val ? node->left : node->right;
        }
        if (node != nullptr) {
            if (node->left == nullptr && node->right == nullptr) {
                if (node == root_) {
                    root_ = nullptr;
                }
                else {
                    node == parent->right ? parent->right = nullptr : parent->left = nullptr;
                }
                delete node;
            }
            else if (node->left == nullptr) {
                node->right->parent = node->parent;
                if (node == root_) {
                    root_ = node->right;
                }
                else {
                    node == parent->right ? parent->right = node->right : parent->left = node->right;
                }
                delete node;
            }
            else if (node->right == nullptr) {
                node->left->parent = node->parent;
                if (node == root_) {
                    root_ = node->left;
                }
                else {
                    node == parent->right ? parent->right = node->left : parent->left = node->left;
                }
                delete node;
            }
            else {
                Node* temp = min(node->right);
                node->value = temp->value;
                if (temp->right != nullptr) {
                    temp->right->parent = temp->parent;
                }
                temp == temp->parent->right ? temp->parent->right = temp->right : temp->parent->left = temp->right;
                delete temp;
            }
            size_--;
        }
    }

    Node* min(Node* node) {
        if (node != nullptr) {
            while (node->left != nullptr) {
                node = node->left;
            }
        }
        return node;
    }

    Node* max(Node* node) {
        if (node != nullptr) {
            while (node->right != nullptr) {
                node = node->right;
            }
        }
        return node;
    }

    void print() {
        print(root_);
        cout << endl;
    }

    int size() const {
        return size_;
    }

    void clear() {
        clear(root_);
        root_ = nullptr;
        size_ = 0;
    }

    Node* find(const T& val) {
        Node* node = root_;
        while (node != nullptr && node->value != val) {
            node = node->value > val ? node->left : node->right;
        }
        return node;
    }

    Node* begin() {
        return min(root_);
    }

    Node* end() {
        return max(root_);
    }

    bool operator==(const Set& other) {
        return size_ == other.size_ ? compare(min(root_), min(other.root_)) : false;
    }

    bool operator!=(const Set& other) {
        return !(*this == other);
    }

    ~Set() {
        clear(root_);
    }

private:

    // вариант сравнения деревьев на случай разной топологии но одинакового размера
    bool compare(Node* a, Node* b) {
        if (a == nullptr && b == nullptr) {
            return true;
        }
        return  a->value == b->value && compare(next(a), next(b));
    }

    Node* next(Node* node) {
        if (node != nullptr) {
            if (node->right != nullptr) {
                return min(node->right);
            }
            Node* temp = node->parent;
            while (temp != nullptr && node->value > temp->value) {
                temp = temp->parent;
            }
            return temp;
        }
        return node;
    }

    Node* prev(Node* node) {
        if (node != nullptr) {
            if (node->left != nullptr) {
                return max(node->left);
            }
            Node* temp = node->parent;
            while (temp != nullptr && node->value < temp->value) {
                temp = temp->parent;
            }
            return temp;
        }
        return node;
    }

    Node* copy(Node* node, Node* parent) {
        if (node == nullptr) {
            return nullptr;
        }
        Node* temp = new Node{ node->value, nullptr, nullptr, parent };
        temp->left = copy(node->left, temp);
        temp->right = copy(node->right, temp);
        return temp;
    }

    void clear(Node* node) {
        if (node != nullptr) {
            clear(node->left);
            clear(node->right);
            delete node;
        }
    }

    void print(Node* node) {
        if (node != nullptr) {
            print(node->left);
            cout << node->value << " ";
            // раскомментировать для проверки построения дерева
           /* cout << " value " << node->value << " ";
            if (node->parent) {
                cout << " parent " << node->parent->value;
            }
            else {
                cout << '\t';
            }
            if (node->left) {
                cout << " left " << node->left->value;
            }
            else {
                cout << '\t';
            }
            if (node->right) {
                cout << " right " << node->right->value;
            }
            else {
                cout << '\t';
            }
            cout << " " << node << endl;*/
            print(node->right);
        }
    }

    Node* root_;
    int size_;
};


int main() {

    setlocale(LC_ALL, "ru");

    Set<int> st{ 45,30,50,27,39,90,15,70,103 };

    st.print();
    cout << st.size() << endl;

    st.print();
    cout << st.size() << endl;

    Set<int> st2(st);

    st2.print();
    cout << st2.size() << endl;

    cout << (st == st2) << endl;

    st2.erase(45);
    st2.insert(45);

    st.print();
    st2.print();

    cout << (st == st2) << endl;

    auto node = st2.find(30);

    if (node != nullptr) {
        cout << node->value << endl;
    }

    Set<string> st3{ "один", "два", "три", "четыре" };

    st3.print();
}