I need help completing this C++ code with these requirements. instructions: IN C++ LANGUAGE PLEASE Update the comments for each prototype by filling in the pre and post conditions. Remember that pre conditions indicate what conditions must be met BEFORE the user calls the function. The function will not work properly unless the pre conditions are met. Post conditions indicate what will be the result of the function call. In other words, what conditions will exist after the function is called. See class notes from Thursday on pre and post conditions for some examples and further explanation. Code begins here: #include //for NULL class List { private: struct Node { int data; Node* next; Node(int data): data(data), next(NULL){} }; typedef struct Node* Nodeptr; Nodeptr first; Nodeptr last; int size; public: /**Constructors and Destructors*/ List(); //Default constructor; initializes and empty list //Postcondition: ~List(); //Destructor. Frees memory allocated to the list //Postcondition: /**Accessors*/ int getFirst(); //Returns the first element in the list //Precondition: int getLast(); //Returns the last element in the list //Precondition: bool isEmpty(); //Determines whether a list is empty. int getSize(); //Returns the size of the list /**Manipulation Procedures*/ void removeLast(); //Removes the value of the last element in the list //Precondition: //Postcondition: void removeFirst(); //Removes the value of the first element in the list //Precondition: //Postcondition: void insertLast(int data); //Inserts a new element at the end of the list //If the list is empty, the new element becomes both first and last //Postcondition: void insertFirst(int data); //Inserts a new element at the start of the list //If the list is empty, the new element becomes both first and last //Postcondition: /**Additional List Operations*/ void printList(); //Prints to the console the value of each element in the list sequentially //and separated by a blank space //Prints nothing if the list is empty }; Solution PROGRAM CODE: #include #include //for NULL using namespace std; class List { private: struct Node { int data; Node* next; Node(int data): data(data), next(NULL){} }; typedef struct Node* Nodeptr; Nodeptr first; Nodeptr last; int size; public: /**Constructors and Destructors*/ List() { first = (Node*) malloc(sizeof(Node)); last = (Node*) malloc(sizeof(Node)); size = 0; } //Default constructor; initializes and empty list //Postcondition: ~List() { delete first; delete last; } //Destructor. Frees memory allocated to the list //Postcondition: /**Accessors*/ int getFirst() { return first->data; } //Returns the first element in the list //Precondition: int getLast() { return last->data; } //Returns the last element in the list //Precondition: bool isEmpty() { if(first == NULL) return true; else return false; } //Determines whether a list is empty. int getSize() { return size; } //Returns the size of the list /**Manipulation Procedures*/ void removeLast() { last = .

1. I need help completing this C++ code with these requirements.
instructions: IN C++ LANGUAGE PLEASE
Update the comments for each prototype by filling in the pre and post conditions.
Remember that pre conditions indicate what conditions must be met BEFORE the user calls the
function. The function will not work properly unless the pre conditions are met.
Post conditions indicate what will be the result of the function call. In other words, what
conditions will exist after the function is called.
See class notes from Thursday on pre and post conditions for some examples and further
explanation.
Code begins here:
#include //for NULL
class List
{
private:
struct Node
{
int data;
Node* next;
Node(int data): data(data), next(NULL){}
};
typedef struct Node* Nodeptr;
Nodeptr first;
Nodeptr last;
int size;
public:
/**Constructors and Destructors*/
List();
//Default constructor; initializes and empty list

2. //Postcondition:
~List();
//Destructor. Frees memory allocated to the list
//Postcondition:
/**Accessors*/
int getFirst();
//Returns the first element in the list
//Precondition:
int getLast();
//Returns the last element in the list
//Precondition:
bool isEmpty();
//Determines whether a list is empty.
int getSize();
//Returns the size of the list
/**Manipulation Procedures*/
void removeLast();
//Removes the value of the last element in the list
//Precondition:
//Postcondition:
void removeFirst();
//Removes the value of the first element in the list

3. //Precondition:
//Postcondition:
void insertLast(int data);
//Inserts a new element at the end of the list
//If the list is empty, the new element becomes both first and last
//Postcondition:
void insertFirst(int data);
//Inserts a new element at the start of the list
//If the list is empty, the new element becomes both first and last
//Postcondition:
/**Additional List Operations*/
void printList();
//Prints to the console the value of each element in the list sequentially
//and separated by a blank space
//Prints nothing if the list is empty
};
Solution
PROGRAM CODE:
#include
#include //for NULL
using namespace std;
class List
{
private:
struct Node
{
int data;
Node* next;
Node(int data): data(data), next(NULL){}

4. };
typedef struct Node* Nodeptr;
Nodeptr first;
Nodeptr last;
int size;
public:
/**Constructors and Destructors*/
List()
{
first = (Node*) malloc(sizeof(Node));
last = (Node*) malloc(sizeof(Node));
size = 0;
}
//Default constructor; initializes and empty list
//Postcondition:
~List()
{
delete first;
delete last;
}
//Destructor. Frees memory allocated to the list
//Postcondition:
/**Accessors*/
int getFirst()
{
return first->data;

5. }
//Returns the first element in the list
//Precondition:
int getLast()
{
return last->data;
}
//Returns the last element in the list
//Precondition:
bool isEmpty()
{
if(first == NULL)
return true;
else return false;
}
//Determines whether a list is empty.
int getSize()
{
return size;
}
//Returns the size of the list
/**Manipulation Procedures*/
void removeLast()
{
last = NULL;
}
//Removes the value of the last element in the list
//Precondition:

6. //Postcondition:
void removeFirst()
{
Nodeptr temp = first;
first = temp->next;
size--;
}
//Removes the value of the first element in the list
//Precondition:
//Postcondition:
void insertLast(int data)
{
if(first->data == 0)
{
first = new Node(data);
last = new Node(data);
}
else
{
Nodeptr temp = last;
last = new Node(data);
temp->next = last;
last = temp;
}
//size++;
}
//Inserts a new element at the end of the list
//If the list is empty, the new element becomes both first and last
//Postcondition:
void insertFirst(int data)
{
if(first->data == 0)
{

7. first = new Node(data);
last = new Node(data);
}
else
{
Nodeptr temp = first;
first = new Node(data);
first->next = temp;
}
size++;
}
//Inserts a new element at the start of the list
//If the list is empty, the new element becomes both first and last
//Postcondition:
/**Additional List Operations*/
void printList()
{
Nodeptr temp = first;
while(temp != NULL)
{
cout<data<<" ";
temp = temp->next;
}
cout<