In this post, we are going to solve the Remove Duplicates from Sorted List II Leetcode Solution problem of Leetcode. This Leetcode problem is done in many programming languages like C++, Java, and Python.

Problem
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.
Now, let’s see the leetcode solution of Remove Duplicates from Sorted List II Leetcode Solution.
Remove Duplicates from Sorted List II Leetcode Solution in Python
class Solution: def deleteDuplicates(self, head: ListNode) -> ListNode: dummy = ListNode(0, head) prev = dummy while head: while head.next and head.val == head.next.val: head = head.next if prev.next == head: prev = prev.next else: prev.next = head.next head = head.next return dummy.next
Remove Duplicates from Sorted List II Leetcode Solution in CPP
class Solution { public: ListNode* deleteDuplicates(ListNode* head) { ListNode dummy(0, head); ListNode* prev = &dummy; while (head) { while (head->next && head->val == head->next->val) head = head->next; if (prev->next == head) prev = prev->next; else prev->next = head->next; head = head->next; } return dummy.next; } };
Remove Duplicates from Sorted List II Leetcode Solution in Java
class Solution { public ListNode deleteDuplicates(ListNode head) { ListNode dummy = new ListNode(0, head); ListNode prev = dummy; while (head != null) { while (head.next != null && head.val == head.next.val) head = head.next; if (prev.next == head) prev = prev.next; else prev.next = head.next; head = head.next; } return dummy.next; } }
Note: This problem Remove Duplicates from Sorted List II is generated by Leetcode but the solution is provided by Chase2learn This tutorial is only for Educational and Learning purposes.