Fixed Push and Pop methods on Stack

C#/Datastructures/Stack.cs

@@ -21,13 +21,15 @@ namespace C_.Datastructures
         }
 
         public void Push(T value){
-            //Add an Item to the top of the stacks
+            //Add an Item to the top of the stack
+            Count++;
             if (Count > 0)
             {    
-                Count++;
                 Head = StackNode<T>.Create(value, Head);
                 return;
             }
+            Head = StackNode<T>.Create(value, default);
+            return;
         }
 
         public T? Pop(){
@@ -38,6 +40,10 @@ namespace C_.Datastructures
                 Count--;
                 value = Head!.Value;
                 Head = Head.Next;
+                if (Count == 0)
+                {
+                    Head = default;
+                }
             }
             return value;
         }