View difference between Paste ID: zrXQGhhc and Lygw2bUj

 #include <stdio.h>
 #include <stdlib.h>
 
 struct dll_node
 {
     int data;
     struct dll_node *prev, *next;
 };
 
 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 remove_list(struct dll_node **node)
 {
     if (NULL == *node)
         return;
 
     struct dll_node *start = *node;
     do
     {
         struct dll_node *next = (*node)->next;
         free(*node);
         *node = next;
     } while (*node != start);
     *node = NULL;
 }
 
 void usun_rek(struct dll_node **ptr,struct dll_node *poczatek)
 {
     if (*ptr)
     {
         if((*ptr)->next!=poczatek)
             usun_rek(&((*ptr)->next),poczatek);
 
         *ptr = delete_node(*ptr,(*ptr)->data);
     }
 }
 
 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);
 
     usun_rek(&dlcl,dlcl);
     puts("aaa");
     print_list(dlcl);
 
     remove_list(&dlcl);
     return 0;
 }