fix removeState, rm addState, add pop override to fit inheritence

pr6.cpp

@@ -421,8 +421,12 @@ protected:
 
 public:
     // Добавление нового государства в начало списка
-    void addState(const State& state) {
+    //void addState(const State& state) {
+    //    stateList.push(state);
+    //}
+    virtual Element<State>* push(const State& state) override {
         stateList.push(state);
+        return stateList.getHead();
     }
     friend ostream& operator<<(ostream& os, const StateList& stateList) {
         Element<State>* current = stateList.stateList.getHead();
@@ -434,6 +438,15 @@ public:
     }
 
     // Удаление государства из начала списка
+    virtual Element<State>* pop() override {
+        try {
+            return new Element<State>(removeState());
+        }
+        catch (const logic_error& e) {
+            cout << e.what() << endl;
+            return nullptr;
+        }
+    }
     State removeState() {
         Element<State>* element = stateList.pop();
         if (element) {
@@ -443,7 +456,6 @@ public:
         }
         throw logic_error("State list is empty");
     }
-
     // Поиск государства по названию
     State* findStateByName(const string& name) {
         Element<State>* current = stateList.getHead();
@@ -588,8 +600,8 @@ int main() {
     StateList* states = new StateList();
  
     //for 6.2
-    states->addState(State("USA", "Washington D.C.", "English", 328000000, 9833510));
+    states->push(State("USA", "Washington D.C.", "English", 328000000, 9833510));
-    states->addState(State("India", "New Delhi", "Hindi", 1380000000, 3287263));
+    states->push(State("India", "New Delhi", "Hindi", 1380000000, 3287263));
 
     // Сохраняем список состояний в файл
     states->save("states.txt");