我如何创建单个列表，然后从中创建两个单个列表，其中一个用于偶数，另一个用于奇数？

Question

I'm a beginner programmer in my first years in college, I'm working with single linked lists in c++, and I'm trying to write a program without using classes to create a single linked list input from a user and print it, then I want to put the even numbers in a new list and print this new list and the odd numbers in another new list and print it too. I began with this, I wish if someone can help me.

#include <iostream>
using namespace std;
struct node {

    int data;
    node* next;
};
struct Even_node {

    int even_data;
    Even_node* even_next;
};
void creat(node*& head, node*& tail)
{
    int num;
    cout << "enter number , (0) to quiet\n";
    cin >> num;

    while (num != 0) {

        node* nptr = new node;
        nptr->data = num;
        if (head == nullptr)

            head = nptr;

        else

            tail->next = nptr;

        tail = nptr;
        tail->next = nullptr;
        cout << "enter number again or 0 to quiet\n";
        cin >> num;
    }
}

void print(node* head)
{
    cout << "the list is:\t";
    while (head != nullptr) {
        cout << head->data << "\t";
        head = head->next;
    }
    cout << endl;
}
main()
{
    node *head = nullptr, *tail = nullptr;
    creat(head, tail);
    print(head);
}

Answer 1

First I fixed the problems

• removed dynamic memory allocations and memory leaks
• it's int main https://en.cppreference.com/w/cpp/language/main_function

#include <iostream>
#include <memory>
using std::cout;
using std::cin;

struct node {
    int data;
    std::unique_ptr<node> next;
};

struct list {
    std::unique_ptr<node> head;
    node *tail;
};

void creat(list &l)
{
    int num;
    cout << "enter number , (0) to quiet\n";
    cin >> num;

    while (num != 0) {
        std::unique_ptr<node> nptr = std::make_unique<node>();
        nptr->data = num;
        if (!l.head) {
            l.head = std::move(nptr);
            l.tail = l.head.get();
        } else {
            l.tail->next = std::move(nptr);
            l.tail = l.tail->next.get();
        }
        cout << "enter number again or 0 to quiet\n";
        cin >> num;
    }
}

void print(const list &l)
{
    auto node = l.head.get();
    cout << "the list is:\t";
    while (node != nullptr) {
        cout << node->data << "\t";
        node = node->next.get();
    }
    cout << '\n';
}

int main()
{
    list l;
    creat(l);
    print(l);
}

Now you can create a second list , call it even , iterate through the first list and copy all even elements into the second list.