Question

link

Given a sorted linked list, delete all duplicates such that each element appear only once.

For example,
Given 1->1->2, return 1->2.
Given 1->1->2->3->3, return 1->2->3.

Stats

Frequency 3
Difficulty 1
Adjusted Difficulty 1
Time to use --------

Ratings/Color = 1(white) 2(lime) 3(yellow) 4/5(red)

Analysis

This question is trivial. The next following up question is not easy.

Code

my code

public ListNode deleteDuplicates(ListNode head) {
    if (head == null) return null;
    ListNode pre = head;
    ListNode post = head;
    while (post != null){
        post = post.next;
        if (post == null || pre.val != post.val){
            pre.next = post;
            pre = post;
        }
    }
    return head;
}