# [83\. Remove Duplicates from Sorted List](https://leetcode.com/problems/remove-duplicates-from-sorted-list/) :::spoiler Solution ```cpp= /** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * ListNode() : val(0), next(nullptr) {} * ListNode(int x) : val(x), next(nullptr) {} * ListNode(int x, ListNode *next) : val(x), next(next) {} * }; */ class Solution { public: ListNode* deleteDuplicates(ListNode* head) { ListNode* cur = head; while (cur && cur->next) { if (cur->val == cur->next->val) { cur->next = cur->next->next; } else { cur = cur->next; } } return head; } }; ``` - 時間複雜度:$O(n)$ - 空間複雜度:$O(1)$ :::