Remove duplicates from sorted list

Linked List

56.3% acceptance

Jan 12, 2026

9794

364

Given the head of a sorted linked list, delete all duplicates such that each element appears only once. Return the linked list sorted as well.

Solution

Rust

Time O(n²)

Space O(1)

LeetCode

solution.rs

impl Solution {
  pub fn delete_duplicates(head: Option<Box<ListNode>>) -> Option<Box<ListNode>> {
    let mut head = head;
    let mut current = &mut head;
    
    while let Some(node) = current {
      while node.next.is_some() && node.next.as_ref().unwrap().val == node.val {
        node.next = node.next.as_mut().unwrap().next.take();
      }
      current = &mut node.next;
    }
    
    head
  }
}