如何删除C ++中添加到链接列表中的最后一个元素

我是第一次使用指针。我有一个程序，可以在链接列表中插入数字，打印列表，然后从列表中删除特定的数字。除我尝试删除最后插入的号码外，它均有效。

节点

#ifndef Node_h
#define Node_h

#include <iostream>
using namespace std;

class Node
{
public:
    int data;
    Node *next;

public:
Node();
};

#endif

Node.cpp

#include "Node.h"

Node::Node()
{
}

LinkedList.h

#ifndef LinkedList_h
#define LinkedList_h

#include "Node.h"

class LinkedList
{
    private:
    Node *pL;

public:
    LinkedList();
    void insert(int nr1);
    void deleteNr(int nr1);
    void printL();
};

#endif

LinkedList.cpp //此程序正在创建数字的“链表”

#include "LinkedList.h"

LinkedList::LinkedList()
{
    pL = NULL;
}

void LinkedList::insert(int nr1)
{
    Node *p = new Node;
    p->data = nr1;
    p->next = pL;
    pL = p;
}

void LinkedList::deleteNr(int nr1)
{
    Node *p = pL;
    Node *p2 = pL;
    while (p != NULL & p->data != nr1)
    {
        p2 = p;
        p = p->next;
    }

    if (p != NULL)
    {
        p2->next = p->next;
        delete p;
    }
}

void LinkedList::printL()
{
    Node *p = pL;

    while (p != NULL)
    {
        cout << p->data << "-> ";
        p = p->next;
    }
}

main.cpp

#include "LinkedList.h"

int menu();

//////// main /////////
int main()
{
    int choice1, nr1;
    LinkedList lk1;

    choice1 = menu();

    while (choice1 <= 3)
    {
        if (choice1 == 1)
        {
            cout << "Enter number." << endl;
            cin >> nr1;
            lk1.insert(nr1);
        }

        else if (choice1 == 2)
        {
            cout << "Enter number." << endl;
            cin >> nr1;
            lk1.deleteNr(nr1);
        }

        else if (choice1 == 3)
        {
            lk1.printL();
            cout << endl << endl;
        }

        else if (choice1 == 4)
        {
            cout << "Exit the program." << endl;
            system("pause");
            exit(1);
        }

        choice1 = menu();
    } // end while loop
}

int menu()
{
    int choice1;

    cout << "1. Insert a number into the linked-list." << endl;
    cout << "2. Delete a number from the linked-list." << endl;
    cout << "3. Print the linked-list." << endl;
    cout << "4. Exit the program." << endl;
    cout << "Enter choice." << endl;
    cin >> choice1;

    return choice1;
}