83. Remove Duplicates from Sorted List*
https://leetcode.com/problems/remove-duplicates-from-sorted-list/
题目描述
Given a sorted linked list, delete all duplicates such that each element appear only once.
Example 1:
Input: 1->1->2
Output: 1->2
Example 2:
Input: 1->1->2->3->3
Output: 1->2->3
C++ 实现 1
链表的题最好引入虚拟节点来做. 新链表保存在 dummy 中, 每次访问新节点 head
, 将其加入到 prev
后面, 然后使用 while (head && head->val == prev->val)
过滤重复节点.
重点还有是最后要设置 prev->next = nullptr;
, 这个不能忘了.
class Solution {
public:
ListNode* deleteDuplicates(ListNode* head) {
if (!head) return nullptr;
ListNode* dummy = new ListNode(0);
auto prev = dummy;
while (head) {
prev->next = head;
prev = prev->next;
head = head->next;
while (head && head->val == prev->val) head = head->next;
}
prev->next = nullptr;
return dummy->next;
}
};