fix segmentation fault by removing Node* in subclasses

Assignment_2/lib/FineList.cpp

@@ -1,12 +1,9 @@
-#pragma once
-
 #include <bits/stdc++.h>
 
 #include"Node.h"
 #include"Set.h"
 
 class FineSet:public Set {
-    Node* first;
     public:
         FineSet();
         bool add(int element);
@@ -17,11 +14,13 @@ class FineSet:public Set {
 FineSet::FineSet() : Set("FineSet") { }
 
 bool FineSet::add(int element) {
-    this->first->lock();
+    first->lock();
+    return true;
     Node* p = this->first;
     Node* c = p->next;
     c->lock();
     while (c->is_smaller_than(element)) {
+        std::cout << "C: "<< c->next << std::endl;
         p->unlock();
         p = c;
         c = c->next;

Assignment_2/lib/LazyList.cpp

@@ -5,7 +5,6 @@
 
 class LazySet:public Set {
     protected:
-        Node* first;
         void locate(int element, Node* prev, Node* cur);
     
     public:

Assignment_2/lib/MultiSet.cpp

@@ -4,7 +4,6 @@
 #include"Set.h"
 
 class MultiSet:public Set {
-    Node* first;
     public:
         MultiSet();
         bool add(int element);

Assignment_2/lib/OptimisticList.cpp

@@ -5,7 +5,6 @@
 
 class OptimisticSet:public Set {
     protected:
-        Node* first;
         bool validate(Node* p, Node* c);
     public:
         OptimisticSet();