Remove Duplicates from Sorted List

Med Given a sorted linked list, delete all nodes that have duplicate numbers, leaving only distinct numbers from the original list.

Thoughts

删除结点肯定需要记录下要被删的结点的next，所以新建next指针

Code

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) { val = x; }
 * }
 */
class Solution {
    public ListNode deleteDuplicates(ListNode head) {
        ListNode node = head;
        if (head == null || head.next == null) {
            return head;
        }
        while (node != null && node.next != null) {     
            if (node.next.val == node.val) {
                ListNode next = node.next.next;
                node.next = next;
            } else {   
                node = node.next;
            }
        }

        return head;
    }
}

Analysis

TC: O(n)