Remove Repeats from Sorted List
Easy
Question
Given the head of a sorted linked list, delete all repeats and return the manipulated linked list. The returned linked list should still be sorted.
Try to solve this problem in O(n) time and O(1) space.
Input: head = [1 -> 1 -> 2 -> 3 -> 3]
Output: [1 -> 2 -> 3]
Input: head = [5 -> 5 -> 5]
Output: [5]
Clarify the problem
What are some questions you'd ask an interviewer?
Understand the problem
What is the resulting list after removing all repeats from the following sorted list? head = [4 -> 7 -> 8 -> 8 -> 9 -> 10 -> 11 -> 11 -> 11 -> 15 -> 15 -> 20]
[4 -> 7 -> 9 -> 10 -> 20]
[20 -> 10 -> 9 -> 7 -> 4]
[4 -> 7 -> 8 -> 9 -> 10 -> 11 -> 15 -> 20]
[20 -> 15 -> 11 -> 10 -> 9 -> 8 -> 7 -> 4]
Take a moment to understand the problem and think of your approach before you start coding.
