TheHappieCat: Reversing Double Linked Lists

reverse_double_linked_list.cpp

// Example program
#include <iostream> // std::cout
#include <utility>  // std::swap
using std::cout;
using std::swap;

struct Node {
    int   data;
    Node* next;
    Node* prev;
};

Node* create_node(int node_data){
    Node* n = new Node();
    n->data = node_data;
    return n;
}

Node* push_node(Node* curr, int node_data){
    if ( curr == nullptr ) return nullptr;

    Node* n = create_node( node_data );
    curr->next = n;
    n->prev = curr;
    return n;
}

Node* create_double_linked_list(int size){
    if(size < 1) return nullptr;

    Node* head = create_node(0);
    Node* curr = head;
    head->prev = nullptr;
    head->next = nullptr;

    for(int i = 1; i < size; i++)
        curr = push_node(curr, i);

    return head;
}

void print_double_linked_list(Node* head){
    Node* curr = head;

    if ( curr == nullptr ) return;

    cout << '\n' << curr->data;
    while ( curr->next )
        curr =  curr->next,
        cout << curr->data;

    cout << '\n' << curr->data;
    while ( curr->prev )
        curr =  curr->prev,
        cout << curr->data;

    cout << '\n';
}

void reverse_double_linked_list(Node* & head){
    // &  -  argument passed by reference
    // That means functions is working on
    // original variable given by caller.

    //Your code here:






}

int main()
{
    Node* head =
     create_double_linked_list(  10  );
      print_double_linked_list( head );
    // You should see:
    // 012345689 \n 9876543210

    reverse_double_linked_list( head );
      print_double_linked_list( head );
    // You should see:
    // 9876543210 \n 0123456789

    // It is an example program.
    // Here is no need to delete allocated memory.
    return 0;
}

My solution:

void reverse_double_linked_list(Node* & head){
    if  ( !head ) return;
    Node*& node = head;

    while( node-> next )
        swap ( node->next, node->prev ),
        node = node->prev; // next

    swap( node->next, node->prev ); // last node
}