c - keep on min max while insert sort - linked list -

i'm trying insert nodes linked list in sorted way, , keep on tail of list , head (which min , max)

this code:

void sortedinsert(automotor **head, automotor *new_car) {     automotor* current;     /* special case head end */     if (*head == null || (*head)->id >= new_car->id)     {         new_car->next = *head;         *head = new_car;     }     else     {         /* locate node before point of insertion */         current = *head;         while (current->next != null && current->next->id < new_car->id)         {             current = current->next;         }         int max = current->id;         new_car->next = current->next;         current->next = new_car;     }     printf("new car add m\n\n"); } 

how can extract min & max (in o(1)) function(i print them)?

thank help

you add 2 parameters, old min , old max (pointers or refs), , update them each time insert.

edited per liona comment:

void sortedinsert(automotor **head, automotor *new_car, automotor **min, automotor **max) {     automotor* current;     /* special case head end */     if (*head == null || (*head)->id >= new_car->id)     {         new_car->next = *head;         *head = new_car;         *min = *head;     }     else     {         /* locate node before point of insertion */         current = *head;         while (current->next != null && current->next->id < new_car->id)         {             current = current->next;         }         //int max = current->id;         new_car->next = current->next;         current->next = new_car;         if ( current->next == null )         {             *max = current;         }     }     printf("new car add m\n\n"); }