/*
83. 删除排序链表中的重复元素
简单

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给定一个已排序的链表的头 head ， 删除所有重复的元素，使每个元素只出现一次 。返回 已排序的链表 。

示例 1：

输入：head = [1,1,2]
输出：[1,2]
示例 2：

输入：head = [1,1,2,3,3]
输出：[1,2,3]

提示：

链表中节点数目在范围 [0, 300] 内
-100 <= Node.val <= 100
题目数据保证链表已经按升序 排列
*/
/**
 * Definition for singly-linked list.
 * function ListNode(val, next) {
 *     this.val = (val===undefined ? 0 : val)
 *     this.next = (next===undefined ? null : next)
 * }
 */
/**
 * @param {ListNode} head
 * @return {ListNode}
 */
import { LinkListNode as ListNode } from '../../list/index.js';

const deleteDuplicates = function (head) {
  let left = head;
  let right = head;
  while (right) {
    if (left.val === right.val) {
      right = right.next;
    } else {
      left.next = right;
      left = right;
    }
  }
  left.next = right;
};
// 示例链表：1 -> 2 -> 3 -> 4 -> 5
const node1 = new ListNode(1);
const node2 = new ListNode(2);
const node3 = new ListNode(2);
const node4 = new ListNode(2);
const node5 = new ListNode(5);
node1.next = node2;
node2.next = node3;
node3.next = node4;
node4.next = node5;

// 删除重复元素
deleteDuplicates(node1);

// 打印反转后的链表
let current = node1;
while (current !== null) {
  console.log(current.val);
  current = current.next;
}