My solution

solution.cpp

@@ -0,0 +1,207 @@
+#include <iostream>
+#include <memory>
+using namespace std;
+class EmptyListError : public runtime_error {
+  static ostringstream cnvt;
+
+public:
+  EmptyListError() : runtime_error("Usage of empty list!") {}
+};
+
+class NotFoundError : public runtime_error {
+
+public:
+  NotFoundError() : runtime_error("Node not found!") {}
+};
+
+class NullNodeError : public runtime_error {
+
+public:
+  NullNodeError() : runtime_error("Cannot add empty Node pointer!") {}
+};
+
+template <typename T> class Node {
+public:
+  Node(const T v) : next(nullptr), previous(nullptr), value(v) {}
+  shared_ptr<Node<T>> next;
+  shared_ptr<Node<T>> previous;
+  T value;
+  ~Node() {
+  	if(next){
+    next->previous = previous;
+}
+	if(previous){
+    previous->next = next;
+}
+    previous=nullptr;
+    next=nullptr;
+  }
+};
+
+template <typename T> class List {
+public:
+  List();
+  ~List();
+  // dodaje element na koniec listy
+  void add(shared_ptr<Node<T>> &&node);   // przenoszenie
+  void add(shared_ptr<Node<T>> &nod);     // kopiowanie
+  shared_ptr<Node<T>> get(const T value); // zwraca element o wskazanej wartości
+  void addFirst(shared_ptr<Node<T>> &nod); // dodaje element na początek listy
+  shared_ptr<Node<T>>
+  getBackward(const T value); // zwraca element o wskazanej wartości od końca
+
+private:
+  shared_ptr<Node<T>> first;
+  shared_ptr<Node<T>> last;
+};
+template <typename T> List<T>::List() : first(nullptr), last(nullptr) {}
+
+template <typename T> void List<T>::add(shared_ptr<Node<T>> &&node) {
+  if (!node) {
+    throw NullNodeError();
+  }
+  if (!first) {
+    first = node;
+  } else if (!first->next) {
+    first->next = node;
+    last = node;
+    last->previous = first;
+  } else {
+    node->previous = last;
+    last->next = node;
+    last = node;
+  }
+  node = nullptr;
+}
+
+template <typename T> void List<T>::add(shared_ptr<Node<T>> &nod) {
+  if (!nod) {
+    throw NullNodeError();
+  }
+  auto node = make_shared<Node<T>>(nod->value);
+  if (!first) {
+    first = node;
+  } else if (!first->next) {
+    first->next = node;
+    last = node;
+    last->previous = first;
+  } else {
+    node->previous = last;
+    last->next = node;
+    last = node;
+  }
+}
+
+template <typename T> void List<T>::addFirst(shared_ptr<Node<T>> &nod) {
+  auto node = make_shared<Node<T>>(nod->value);
+  if (!nod) {
+    throw NullNodeError();
+  }
+  if (!first) {
+    first = node;
+  } else {
+    first->previous = node;
+    node->next = first;
+    first = node;
+  }
+}
+template <typename T> shared_ptr<Node<T>> List<T>::get(const T value) {
+  if (!first) {
+    throw EmptyListError();
+    return nullptr;
+  } else {
+    shared_ptr<Node<T>> current = first;
+    do {
+      if (current->value == value) {
+        cout << "Found value " << current->value << endl;
+        return current;
+      } else {
+        cout << "Going through " << current->value << endl;
+        current = current->next;
+      }
+    } while (current);
+    throw NotFoundError();
+    return nullptr;
+  }
+}
+
+template <typename T> shared_ptr<Node<T>> List<T>::getBackward(const T value) {
+  shared_ptr<Node<T>> current = last;
+  if (!last) {
+    current = first;
+  }
+
+  if (!first) {
+    throw EmptyListError();
+    return nullptr;
+  } else {
+    do {
+      if (current->value == value) {
+        cout << "Found value " << current->value << endl;
+        return current;
+      } else {
+        cout << "Going through " << current->value << endl;
+        current = current->previous;
+      }
+    } while (current);
+    throw NotFoundError();
+    return nullptr;
+  }
+}
+
+template <typename T> List<T>::~List() {
+  while (last->previous) {
+    shared_ptr<Node<T>> current = last->previous;
+    last = nullptr;
+    current->next = nullptr;
+    last = current;
+  }
+}
+int main() {
+  List<string> lista;
+  auto nodeNapis = make_shared<Node<string>>("napis");
+  auto nodeElo = make_shared<Node<string>>("elo");
+  auto nodeHello = make_shared<Node<string>>("hello");
+  cout << "Empty list exceptions:" << endl;
+  cout << "------------------------------" << endl;
+  try {
+    lista.get("text");
+  } catch (const EmptyListError &e) {
+    cout << e.what() << endl;
+  }
+  cout << "------------------------------" << endl << endl;
+
+  lista.add(nodeElo);
+  lista.add(move(nodeHello));
+  lista.addFirst(nodeNapis);
+
+  cout << "Nullptr exceptions:" << endl;
+  cout << "------------------------------" << endl;
+  try {
+    lista.add(move(nodeHello));
+  } catch (const NullNodeError &e) {
+    cout << e.what() << endl;
+  }
+  try {
+    lista.add(nullptr);
+  } catch (const NullNodeError &e) {
+    cout << e.what() << endl;
+  }
+
+  cout << "------------------------------" << endl << endl;
+  cout << "Not found exceptions:" << endl;
+  cout << "------------------------------" << endl;
+  try {
+    auto node = lista.get("text");
+  } catch (const NotFoundError &e) {
+    cout << e.what() << endl;
+  }
+  try {
+    auto node = lista.getBackward("text");
+  } catch (const NotFoundError &e) {
+    cout << e.what() << endl;
+  }
+  cout << "------------------------------" << endl << endl;
+
+  return 0;
+}