Compilation failed with errors:

$/$usr$/$bin$/$ld: build$/$main$.$o:$(.$bss$+0$x$0)$: multiple definition of $`$DNode::activeNodes'; build$/$DNode$.$o:$(.$bss$+0$x$0)$: first defined here

collect$2$: error: ld returned $1$ exit status

make: $***[$Makefile:$20$: build$/$main$\_185\_44\_2]$ Error $1$

Recommendation: Check for recursive inclusion, unhandled exceptions, logical errors, or syntax issues in the code.Submission Status: Failed

$------------------------------$

$===$ Automatic Test Results $===$

$------------------------------$

Compilation failed with errors:

$/$usr$/$bin$/$ld: build$/$main$.$o:$(.$bss$+0$x$0)$: multiple definition of $`$DNode::activeNodes'; build$/$DNode$.$o:$(.$bss$+0$x$0)$: first defined here

collect$2$: error: ld returned $1$ exit status

make: $***[$Makefile:$20$: build$/$main$\_185\_44\_2]$ Error $1$Recommendation: Check for recursive inclusion, unhandled exceptions, logical errors, or syntax issues in the code.

pls help here is my code:

$//$DLinkedList$.$cpp

#include "DLinkedList.h$"$

#include

DLinkedList::DLinkedList$()$ : head$($nullptr$),$ trailer$($nullptr$),$ listSize$(0)\{\}$

DLinkedList::~DLinkedList$()\{$

while $(!$empty$())$ removeFront$()$;

$\}$

bool DLinkedList::empty$()$ const $\{$

return head $==$ nullptr;

$\}$

const int& DLinkedList::front$()$ const $\{$

return head$->$elem;

$\}$

const int& DLinkedList::back$()$ const $\{$

return trailer$->$elem;

$\}$

void DLinkedList::addFront$($const int& e$)\{$

DNode$*$ newNode $=$ new DNode$($e$,$ nullptr, head$)$;

if $($empty$())\{$

head $=$ trailer $=$ newNode;

$\}$ else $\{$

head$->$prev $=$ newNode;

head $=$ newNode;

$\}$

listSize$++$;

$\}$

void DLinkedList::addBack$($const int& e$)\{$

DNode$*$ newNode $=$ new DNode$($e$,$ trailer, nullptr$)$;

if $($empty$())\{$

head $=$ trailer $=$ newNode;

$\}$ else $\{$

trailer$->$next $=$ newNode;

trailer $=$ newNode;

$\}$

listSize$++$;

$\}$

void DLinkedList::removeFront$()\{$

if $($empty$())$ return;

DNode$*$ oldNode $=$ head;

if $($head $==$ trailer$)\{$

head $=$ trailer $=$ nullptr;

$\}$ else $\{$

head $=$ head$->$next;

head$->$prev $=$ nullptr;

$\}$

delete oldNode;

listSize$--$;

$\}$

void DLinkedList::removeBack$()\{$

if $($empty$())$ return;

DNode$*$ oldNode $=$ trailer;

if $($head $==$ trailer$)\{$

head $=$ trailer $=$ nullptr;

$\}$ else $\{$

trailer $=$ trailer$->$prev;

trailer$->$next $=$ nullptr;

$\}$

delete oldNode;

listSize$--$;

$\}$

void DLinkedList::print$($bool front$)$ const $\{$

if $($empty$())$ return;

if $($front$)\{$

DNode$*$ node $=$ head;

while $($node $!=$ nullptr$)\{$

std::cout $<<$ node$->$elem $<<""$;

node $=$ node$->$next;

$\}$

$\}$ else $\{$

DNode$*$ node $=$ trailer;

while $($node $!=$ nullptr$)\{$

std::cout $<<$ node$->$elem $<<""$;

node $=$ node$->$prev;

$\}$

$\}$

std::cout $<<$ std::endl;

$\}$

int DLinkedList::size$()$ const $\{$

return listSize;

$\}$

int DLinkedList::activeNodeCount$()$ const $\{$

return DNode::activeNodes;

$\}$

$//$DNode$.$cpp

#include "DNode.h$"$

$//$ Define the static member variable

int DNode::activeNodes $=0$;

DNode::DNode$($int e$,$ DNode$*$ p$,$ DNode$*$ n$)$ : elem$($e$),$ prev$($p$),$ next$($n$)\{$

activeNodes$++$;

$\}$

DNode::~DNode$()\{$

activeNodes$--$;

$\}$

$//$DLinkedList$.$h

#ifndef DLINKEDLIST$\_$H

#define DLINKEDLIST$\_$H

#include "DNode.h$"$

class DLinkedList $\{$

private:

DNode$*$ head; $//$ Pointer to the first node

DNode$*$ trailer; $//$ Pointer to the last node

int listSize; $//$ Stores the current number of elements in the list

public:

DLinkedList$()$; $//$ Constructor

~DLinkedList$()$; $//$ Destructor

bool empty$()$ const; $//$ Check if the list is empty

const int& front$()$ const; $//$ Get front element

const int& back$()$ const; $//$ Get back element

void addFront$($const int& e$)$; $//$ Add to the front of the list

void addBack$($const int& e$)$; $//$ Add to the back of the list

void removeFront$()$; $//$ Remove front item from the list

void removeBack$()$; $//$ Remove back item from the list

void print$($bool front $=$ true$)$ const; $//$ Print the list

int size$()$ const; $//$ Returns the current number of elements in the list

int activeNodeCount$()$ const; $//$ Return the count of active DNodes

$\}$;

#endif $//$ DLINKEDLIST$\_$H

$//$main$.$cpp

#include "DLinkedList.h$"$

#include

int main$()\{$

DLinkedList list;

list.addFront$(10)$;

list.addFront$(20)$;

list.addFront$(30)$;

list.addBack$(40)$;

list.addBack$(50)$;

std::cout $<<$ "List from head: $"$;

list.print$($true$)$;

std::cout $<<$ "List from trailer: $"$;

list.print$($false$)$;

list.removeFront$()$;

list.removeBack$()$;

std::cout $<<$ "List after removals: $"$;

list.print$($true$)$;

list.addFront$(60)$;

list.addBack$(70)$;

std::cout $<<$ "List after adding more elements: $"$;

list.print$($true$)$;

std::cout $<<$ "Active nodes: $"<<$ list.activeNodeCount$()<<$ std::endl;

return $0$;

$\}$

$//$DNode$.$h

#ifndef DNODE$\_$H

#define DNODE$\_$H

class DNode $\{$

private:

int elem; $//$ Element stored in the node

DNode$*$ prev; $//$ Pointer to the previous node

DNode$*$ next; $//$ Pointer to the next node

public:

static int activeNodes; $//$ Sta