双向链表的创建插入删除

#include <iostream>
#include<fstream>

using namespace std;
//typedef struct Node{
//    int value;
//    struct Node *next;
//}Node;
class Node{
public :
    Node():data(0),last(nullptr),next(nullptr){}
    Node(int bv,class Node* bp1,class Node* bp2):data(bv),last(bp1),next(bp2){}
public :
    int data;
    class Node* next;
    class Node* last;
};
Node *headNode,*tailNode;
int listlen;
void initlist();
void inselist(int kdata);
void delelist();
void outlist();

int main()
{
    int insedata = 0;
    cin >> listlen;
    initlist();
    cin >> insedata;
    inselist(insedata);
    outlist();
    delelist();
    return 0;
}
void initlist()
{
    int data;
    Node *tempNode = nullptr;
    cin >> data;
    headNode = new Node(data,nullptr,nullptr);
    tempNode = headNode;
    for(int i=1; i<listlen; ++i){
        cin >> data;
        tempNode->next = new Node(data,tempNode,nullptr);
        tempNode = tempNode->next;
    }
    tailNode = tempNode;
}
void inselist(int kdata)
{
    Node *tempNode = headNode;
    Node *inseNode = new Node(kdata,nullptr,nullptr);
    while(tempNode){
        if(tempNode->data >= kdata){
            break;
        }
        tempNode = tempNode->next;
    }
    if(tempNode == headNode){
        headNode->last = inseNode;
        inseNode->next = headNode;
        headNode = inseNode;
    }
    else if(tempNode == nullptr){
        tailNode->next = inseNode;
        inseNode->last = tailNode;
        tailNode = inseNode;
    }
    else{
        (tempNode->last)->next = inseNode;
        inseNode->last = tempNode->last;
        inseNode->next = tempNode;
        tempNode->last = inseNode;
    }
}
void outlist()
{
    Node *tNode = headNode;
    ofstream outf("out.txt",ios::out);

    while(tNode){
        if(tNode == headNode)cout << tNode->data;
        else cout << " " << tNode->data;
        tNode = tNode->next;
    }
    outf << endl;
    outf.close();
}
void delelist()
{
    Node *tNode = headNode;
    Node *tnext;
    while(tNode){
        tnext = tNode->next;
        delete tNode;
        tNode = tnext;
    }
}