题解 | #删除有序链表中重复的元素-II#

/*
 * function ListNode(x){
 *   this.val = x;
 *   this.next = null;
 * }
 */

/**
 *
 * @param head ListNode类
 * @return ListNode类
 */
function deleteDuplicates(head) {
  // write code here
  if (head == null) return head;
  const dummyNode = new ListNode(-1);
  dummyNode.next = head;
  let cur = dummyNode;
  while (cur.next && cur.next.next) {
    if (cur.next.val === cur.next.next.val) {
      const temp = cur.next.val;
      while (cur.next && cur.next.val === temp) {
        cur.next = cur.next.next;
      }
    } else {
      cur = cur.next;
    }
  }
  return dummyNode.next;
}
module.exports = {
  deleteDuplicates: deleteDuplicates,
};