모던한 개발

#include <iostream>

struct Node{

    Node* prev;
    Node* next;

    void* data;
};

struct List{
    Node* head;
};

List* createList(){

    Node* head = new Node;
    head->prev = head;
    head->next = head;
    head->data = 0;

    List* list = new List;
    list->head = head;

    return list;
}

void insertNodeAfter(Node* node, void* data){
    
    Node* before = node;
    Node* after = node->next;

    Node* newNode = new Node;
    newNode->data = data;
    newNode->next = after;
    newNode->prev = before;

    after->prev = newNode;
    before->next = newNode;
}

void removeNode(Node* node, bool deleteData){

    Node* before = node->prev;
    Node* after = node->next;

    before->next = after;
    after->prev = before;

    if (deleteData)
        delete node->data;
    delete node;
}
............................................
// 이하생략 이만큼의 코드로도 리스트가 제대로 작동하지않는다.
// 또한 스레드 세이프하기위해서 더 신경쓰야할 부분도있다.

#include <algorithm>
#include <iostream>
#include <list>
 
int main()
{
    // Create a list containing integers
    std::list<int> l = { 7, 5, 16, 8 };
 
    // Add an integer to the front of the list
    l.push_front(25);
    // Add an integer to the back of the list
    l.push_back(13);
 
    // Insert an integer before 16 by searching
    auto it = std::find(l.begin(), l.end(), 16);
    if (it != l.end()) {
        l.insert(it, 42);
    }
 
    // Iterate and print values of the list
    for (int n : l) {
        std::cout << n << '\n';
    }
}

List<Person> persons = new List<Person>()
{
    new Person { PersonId = 1, car = "Ferrari" },
    new Person { PersonId = 1, car = "BMW" },
    new Person { PersonId = 2, car = "Audi"}
};


List<Result> results2 = persons
    .GroupBy(p => p.PersonId, 
             (k, c) => new Result()
                     {
                         PersonId = k,
                         Cars = c.Select(cs => cs.car).ToList()
                     }
            ).ToList();