存档链表

#include <bits/stdc++.h> 
#include <iostream>

//链表的构造插入查找输出 
using namespace std;

//链表节点定义 
struct Node{
    int val;
    Node *next;
    Node(int x) : val(x),next(NULL){};
    };

//头插法建立单链表  
Node* CreateListByHead(int arr[],int n){
    Node* head = NULL;

    for(int i = 0;i<n;i++){
        Node *node = new Node(arr[i]);

        if(head == NULL) head = node;
        else
        {
            node->next = head;
            head = node; 
        }
    }
}

//带虚拟头结点的头插法 
Node* CreateListwithHead(int arr[],int n)
{

    //创建虚拟头结点
    Node *dummy = new Node(-1);

    for(int i = 0;i<n;i++){
        //创建新节点 
        Node *node = new Node(arr[i]);

        node->next = dummy->next;
        dummy->next = node; 
    }
    return dummy->next;
}

//尾插法建立单链表 
Node* CreateListBytail(int arr[],int n)
{
    Node *head = nullptr;
    Node *tail = nullptr;   

    for(int i = 0;i<n;i++){

    //创建新节点 
    Node *node = new Node(arr[i]);

    //如果链表为空
    if (head == nullptr) 
    {
        head = node;
        tail = node;
    }
    else
    {
        tail->next = node;
        tail = node;
    } 
}

//带虚拟头结点的尾插法 
Node* CreateListWithtail(int arr[],int n)
{
    Node *dummy =  new Node(-1);
    Node *tail = dummy;

    for(int i = 0;i<n;i++)
    {
        //创建节点 
        Node *node = new Node(arr[i]);

        tail->next = node;
        tail = node;            
        }
    return dummy->next;
}

//插入 
Node *insertNode(Node *head,int index,int x)
{
    Node *p = head;
    Node *newnode = new Node(x);

    for(int i = 0;i<index-1;i++)    
        p = p->next;

    newnode->next = p->next;
    p->next = newnode;
}

//删除
Node *deleteNode(Node *head,int index,int x)
{
    Node *p = head;

    for(int i = 0;i<index-1;i++)    
        p = p->next;

    x = p->next->val;
    p->next = p->next->next;
}

//查找，索引查找 
Node *getNodebyindex(Node *head,int i)
{
    Node *p = head;
    for(;i = 0;i--) 
    {
        p = p->next;
        return p;
    }
}

//查找，值查找 
Node *getNodebyval(Node *head,int e)
{
    for(Node *p = head;p;p = p->next)
    {
        if(p->val ==  e); 
        return p;
    }
}

//遍历输出 
void print(Node *head)
{
    for (Node *p = head;p;p = p->next)
    {
        cout<<p->val<<' ';
        cout<<endl;
    }   
}

int main(){
    int a[] = {[0]:1,[1]:1,[2]:5,[3]:1};
    int n = sizeof(a) / sizaof(int);

    Node *head = CreateListWithtail(a,n);
    print(head);

    insertNode(head, 2, 0);
    print(head);

    return 0;
}