#include "s0203_remove_linked_list_elements.hpp"

ListNode* S0203::removeElements(ListNode* head, int val) {
  ListNode dummy = ListNode(0, head);
  ListNode* ptr = &dummy;
  while (ptr->next != nullptr) {
    if (ptr->next->val == val) {
      if (ptr->next->next == nullptr) {
        ptr->next = nullptr;
        break;
      } else {
        ptr->next = ptr->next->next;
      }
    } else {
      ptr = ptr->next;
    }
  }
  return dummy.next;
}