Knoten löschen aus verketteter Liste mit bestimmten Wert

Ich bin derzeit ein Programm schreiben, das eine Funktion muss um einen node zu löschen, basierend auf den Wert.

Ich habe versucht und versucht, um es herauszufinden.

Alles, was ich habe, so weit ist die Funktion Signatur:

NODE* delete_node(NODE * ptr, int n, int *success_flag)

Meine verkettete Liste als follow Struktur:

/* declaration of structure */
typedef struct node
{
  int data;
  struct node *next;
} NODE;

Heres einige der code, den ich bereits über ein anderes Anliegen:

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

/* declaration of structure */
typedef struct node
{
  int data;
  struct node *next;
} NODE;

/* declaration of functions */
NODE* insert_node(NODE *ptr, NODE *new);
NODE* find_node(NODE *ptr, int n);
NODE* delete_node(NODE *ptr, int n, int *success_flag_ptr);
void print_backward_iteration(NODE *ptr);
void print_backward_recursion(NODE *ptr);

int main(int argc, char *argv[])
{
  int choice, x, flag_success;
  NODE *ptr, *new, *result;

  ptr = NULL;

  do
    {

      printf("\n1.\tInsert Integer into linked list\n");
      printf("2.\tFind integer in linked list\n");
      printf("3.\tDelete integer from linked list\n");
      printf("4.\tPrint out integers backward using the iterative strategy\n");
      printf("5.\tPrint out integers backward using the recursive strategy\n");
      printf("6.\tQuit\n");
      printf("\nEnter 1,2,3,4,5, or 6: ");
      scanf("%d", &choice);

      switch(choice)
    {
    case 1:

      printf("\nPlease enter an integer: ");
      scanf("%d", &x);
      new = (NODE *)malloc(sizeof(NODE));
      new->data = x;
      ptr = insert_node(ptr, new);
      printf("\nNode Inserted with value of %d.\n", ptr->data);
      break;

    case 2:

      printf("\nPlease enter an integer: ");
      scanf("%d", &x);
      result = find_node(ptr, x);

      if (result == NULL)
        {
          printf("\nValue could not be found.\n");
        }
      else
        {
          printf("\nValue %d was found.\n", x);
        }

      break;

    case 3:
      printf("\nPlease enter an integer: ");
      scanf("%d", &x);
      ptr = delete_node(ptr, x, &flag_success);

        if (result == NULL)
        {
          printf("\nValue could not be found.\n");
        }
      else
        {
          printf("\nValue %d was deleted.\n", x);
        }

      break;

    case 4:

      print_backward_iteration(ptr);
      break;

    case 5:

      printf("\n");
      print_backward_recursion(ptr);
      printf("\n");

      break;

    case 6:
      printf("\nThank you for using this program.\n");
    break;

    default:
      printf("\nInvalid Choice. Please try again.\n");
      break;

    }
    }
  while (choice != 6);

  printf("\n*** End of Program ***\n");
  return 0;
}

/* definition of function insert_node */
NODE* insert_node(NODE *ptr, NODE *new)
{

 new -> next = ptr;
 return new;

}

/* definition of function find_node */
NODE* find_node(NODE *ptr, int n)
{

  while (ptr != NULL)
    {
      if (ptr->data == n)  
    {
      return ptr;
    }
      else
    {
      ptr = ptr->next;
    }
    }
  return NULL;
  }

/* definition of function print_backward_iteration */
void print_backward_iteration(NODE *ptr)
{
  NODE *last, *current;

  last = NULL;

  printf("\n");

  while (ptr != last)
    {
      current = ptr;

      while (current != last)
    {
      current =  current -> next;
    }

      printf("%d  ", current -> data);
      last = current -> next;
    }

    printf("\n");

}

/* definition of function print_backward_recursion */
void print_backward_recursion(NODE *ptr)
{
  NODE *last, *current;

  last = NULL;

  while (ptr != last)
      {
    current = ptr;
    printf("%d  ", current -> data);
    print_backward_recursion(current -> next);
    last = current;
      }

}