Сортировка списка(классовый) C++

я не могу написать сортировку списка только парных рядов,помогите пожалуйста. Заранее спасибо.

#include <iostream>
using namespace std;
class List {
public:
    List();
    void push_back(int number, int i, int j);
    int GetSize() {
        return Size;
    }
    void print(int n);
    void print_task(int n);
    void printwithnulls(int n);
private:
    class Node {
    public:
        Node* pNext;
        int number;
        int i;
        int j;
        int actualI;
        int actualJ;
        Node(int number, int i, int j, Node* pNext = nullptr) {
            this->number = number;
            this->i = i;
            this->j = j;
            this->pNext = pNext;
        }
    };
    int Size;
    Node* head;
};

List::List() {
    Size = 0;
    head = nullptr;
}

void List::push_back(int number, int i, int j) {
    if (head == nullptr) {
        head = new Node(number, i, j);
    }
    else {
        Node* current = this->head;
        while (current->pNext != nullptr) {
            current = current->pNext;
        }
        Node* newNode = new Node(number, i, j);
        current->pNext = newNode;
    }
    Size++;
}
void List::print(int n) {
    if (Size != 0) {
        int searchI = 0;
        int searchJ = 0;
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < n; j++) {
                Node* current = this->head;
                while (current != nullptr)
                {
                    if (current->i == i && current->j == j) {
                        current->actualI = searchI;
                        current->actualJ = searchJ;
                        searchJ++;
                        cout << current->number<< " ";
                    }
                    current = current->pNext;
                }

            }
            searchI++;
            searchJ = 0;
            cout << endl;
        }
    }
    else {
        cout << endl << "Size of list == 0";
    }
}
void List::printwithnulls(int n) {
    if (Size != 0) {
        bool checked = false;
        int searchI = 0;
        int searchJ = 0;
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < n; j++) {
                checked = false;
                Node* current = this->head;
                while (current != nullptr)
                {
                    if (current->i == i && current->j == j) {
                        checked = true;
                        current->actualI = searchI;
                        current->actualJ = searchJ;
                        searchJ++;
                        cout << current->number
                            << " ";
                    }
                    current = current->pNext;
                }
                if (!checked) {
                    cout << "0 ";
                }
            }
searchI++;
searchJ = 0;
cout << endl;
    }
  }
  else {
  cout << endl << "Size of list == 0";
  }
}
void List::print_task(int n) {
    if (Size != 0) {
        for (int i = 0; i < n; i++) {
            int temp;
            Node* current = this->head;
            while (current != nullptr)
            {
                //сортировка
                current = current->pNext;
            }           
            cout << endl;
        }
    }
    else {
        cout << endl << "Size of list == 0";
    }
}

int main()
{
    List lst;
    int n;
    cout << "Enter n of matrix: ";
    cin >> n;
    int** matrix = new int* [n];
    for (int i = 0; i < n; i++) {
        matrix[i] = new int[n];
    }
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            matrix[i][j]=0;
        }
    }
    int d = ((n*n) / 2) - 1;
    for (int i = 0; i < d; i++) {
            matrix[rand()%n][rand() % n] = rand() % 8+1;
    }
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            if (matrix[i][j] != 0) {
                lst.push_back(matrix[i][j], i, j);
            }
        }
    }
    cout << "matrix:" << endl;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            cout << matrix[i][j] << " ";
        }
        cout << endl;
    }
    cout << "First matrix : " << endl;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            if (i < n / 2 && j > n / 2) {
                cout << matrix[n / 2 + i + 1][j - n / 2 - 1] << " ";
            }
            else if (i > n / 2 && j < n / 2) {
                cout << matrix[i - n / 2 - 1][j + n / 2 + 1] << " ";
            }
            else {
                cout << matrix[i][j] << " ";
            }
        }
        cout << endl;
    }
    cout << "Szhataya matrix: " << endl;
    lst.print(n);
    cout << endl;
    cout << "Szhataya matrix po zadaniyu: " << endl;
    lst.print_task(n);
    cout << "Rozkritaya matrica: " << endl;
    lst.printwithnulls(n);
}