#include <stdio.h>
#include <stdlib.h>

struct dll_node
{
    int data ;
    struct dll_node *prev, * next ;
}*list_pointer;

struct dll_node * create_list ( int data )
{
    struct dll_node * new_node = ( struct dll_node *)
                                 malloc ( sizeof ( struct dll_node ) ) ;
    if ( NULL != new_node )
    {
        new_node -> data = data ;
        new_node -> prev = new_node -> next = new_node ;
    }
    return new_node ;
}

struct dll_node * find_max_node ( struct dll_node * node )
{
    struct dll_node * start = node, * result = node ;
    int maximum = node -> data ;
    do
    {
        if ( maximum < node -> data )
        {
            maximum = node -> data ;
            result = node ;
        }
        node = node -> next ;

    }
    while ( node != start ) ;
    return result ;
};

struct dll_node * find_next_node ( struct dll_node *node, int data )
{
    node = find_max_node ( node ) ;
    struct dll_node * start = node ;
    do
    {
        if (node -> data < data )
            break ;
        node = node -> next ;
    }
    while ( node != start ) ;
    return node ;
};

void insert_node ( struct dll_node *node, int data )
{
    if ( NULL == node )
        return ;

    struct dll_node * new_node = ( struct dll_node *)
                                 malloc ( sizeof ( struct dll_node ) ) ;
    if ( NULL != new_node )
    {
        new_node -> data = data ;
        node = find_next_node (node, data ) ;
        new_node -> next = node ;
        new_node -> prev = node -> prev ;
        node ->prev -> next = new_node ;
        node -> prev = new_node ;
    }
}

struct dll_node * delete_node ( struct dll_node *node, int data )
{
    if ( NULL == node )
        return NULL ;

    node = find_next_node (node, data ) ;
    node = node -> prev ;
    if (node -> data == data )
    {
        if ( node == node -> next )
        {
            free ( node ) ;
            return NULL ;
        }
        else
        {
            struct dll_node * next = node -> next ;
            node ->prev -> next = node -> next ;
            node ->next -> prev = node -> prev ;
            free ( node ) ;
            node = next ;
        }
    }

    return node ;
}

void print_list ( struct dll_node * node )
{
    if ( NULL == node )
        return ;

    node = find_max_node ( node ) ;
    struct dll_node * start = node ;
    do
    {
        printf ("%d ", node -> data ) ;
        node = node -> next ;
    }
    while ( node != start ) ;
    printf ("\n") ;
}

void clear_list (struct dll_node* start, struct dll_node ** node )
{

    if(NULL == *node)
    {
        return ;
    }
    if ( start !=  (*node)->next )
    {
        clear_list(start,&(*node)->next ) ;
        free (*node ) ;
    }
        *node = NULL;
}

int main ()
{
    struct dll_node * dlcl = create_list (1) ;
    int i;

    for (i=2; i <5; i++)
        insert_node (dlcl, i) ;
    for (i=6; i <10; i++)
        insert_node (dlcl, i) ;
    printf (" List elements :\n") ;
    print_list ( dlcl ) ;

    insert_node (dlcl, 0) ;
    printf (" List elements after insertion of 0:\n") ;
    print_list ( dlcl ) ;
    insert_node (dlcl, 5) ;
    printf (" List elements after insertion of 5:\n") ;
    print_list ( dlcl ) ;
    insert_node (dlcl, 7) ;
    printf (" List elements after insertion of 7:\n") ;
    print_list ( dlcl ) ;
    insert_node (dlcl, 10) ;
    printf (" List elements after insertion of 10:\n") ;
    print_list ( dlcl ) ;


    dlcl = delete_node (dlcl, 0) ;
    printf (" List elements after deletion of 0:\n") ;
    print_list ( dlcl ) ;
    dlcl = delete_node (dlcl, 1) ;
    printf (" List elements after deletion of 1:\n") ;
    print_list ( dlcl ) ;
    dlcl = delete_node (dlcl, 1) ;
    printf (" List elements after deletion of 1:\n") ;
    print_list ( dlcl ) ;
    dlcl = delete_node (dlcl, 5) ;
    printf (" List elements after deletion of 5:\n") ;
    print_list ( dlcl ) ;
    dlcl = delete_node (dlcl, 7) ;
    printf (" List elements after deletion of 7:\n") ;
    print_list ( dlcl ) ;
    dlcl = delete_node (dlcl, 10) ;
    printf (" List elements after deletion of 10:\n") ;
    print_list ( dlcl ) ;

    clear_list(dlcl,&dlcl);
    printf("Elementy po usunieciu listy: \n");
    print_list ( dlcl ) ;

    return 0;
}