Remove Duplicates from Sorted List Easy 0 attempts
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Remove Duplicates from Sorted List

Easy Linked List LeetCode

You get the head of a singly linked list whose values are sorted in non-decreasing order. Remove duplicates so each value appears at most once. Keep the list sorted. Return the head of the modified list.

Do not allocate a whole new list for the result; reuse nodes and adjust pointers.

Example 1

  • Input: head = [1, 1, 2]
  • Output: [1, 2]

Example 2

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

Constraints

  • The list has between 0 and 300 nodes
  • -100 <= Node.val <= 100
  • The list is sorted in non-decreasing order
Sample Input
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Sample Output
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Constraints
  • 0 to 300 nodes
  • -100 <= Node.val <= 100
  • List is sorted in ascending order
Topics
Linked List

One Pass

function deleteDuplicates(head) {
  let curr = head;
  while (curr && curr.next) {
    if (curr.val === curr.next.val) curr.next = curr.next.next;
    else curr = curr.next;
  }
  return head;
}

Time: O(n) | Space: O(1)

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