This is doubly-linked list problem from c++

Can someone please explain to me the problem below the line by line with some pictures if possible

How will the list be arranged after running the code segment below? Assume the default value for a node is 0, and the overloaded constructors parameters are in this order: data, previous pointer, next pointer.

FIRST? LAST?

P1?

P2?

P3?

PRINT?

void DoublyList::createlist() { Node *p1 = new Node(1, nullptr, nullptr); Node *p2 = new Node(2, p1, nullptr); Node *p3 = new Node (3, p2, p1); p1->setNext(new Node(4, p3, p2)); first = p3; p1 p1->getNext(); p3->getNext() ->setData(5); p2->getPrev()->setPrev(first->getNext()); p2 nullptr; P3->getPrev() ->setPrev(p1); p1->getPrev()->setPrev(p2); last = p1->getNext(); p1->setPrev(p3->getNext()); P3->setPrev(p1->getNext()); p1->getPrev()->setPrev(p3); p3 = P2; first->setPrev(nullptr); } reso C