82. Remove Duplicates from Sorted List II

🟠   🔖  链表 双指针  🔗 LeetCode

题目

Given the head of a sorted linked list, delete all nodes that have duplicate numbers, leaving only distinct numbers from the original list. Return the linked list sorted as well.

Example 1:

Input: head = [1,2,3,3,4,4,5]

Output: [1,2,5]

Example 2:

Input: head = [1,1,1,2,3]

Output: [2,3]

Constraints:

• The number of nodes in the list is in the range [0, 300].
• -100 <= Node.val <= 100
• The list is guaranteed to be sorted in ascending order.

题目大意

删除链表中重复的结点，只要是有重复过的结点，全部删除。

解题思路

按照题意做即可。

代码

/**
 * @param {ListNode} head
 * @return {ListNode}
 */
var deleteDuplicates = function (head) {
  let obj = {};
  let res = new ListNode(0, head);
  let prev = res;

  while (prev.next && prev.next.next) {
    if (prev.next.val === prev.next.next.val) {
      // 删除与 prev.next 重复的节点
      while (
        prev.next &&
        prev.next.next &&
        prev.next.val === prev.next.next.val
      ) {
        prev.next = prev.next.next;
      }
      // 删除 prev.next 节点
      prev.next = prev.next.next;
    } else {
      prev = prev.next;
    }
  }
  return res.next;
};

相关题目

相关题目

• 83. 删除排序链表中的重复元素
• 🔒 Remove Duplicates From an Unsorted Linked List

- [83. 删除排序链表中的重复元素](./0083.md)
- [🔒 Remove Duplicates From an Unsorted Linked List](https://leetcode.com/problems/remove-duplicates-from-an-unsorted-linked-list)