83 Remove Duplicates from Sorted List

题目链接：https://leetcode.com/problems/remove-duplicates-from-sorted-list/

题目：

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.

解题思路：
这道题很简单，不做过多累述。
需要注意的是，每次更新 p 指针后都应该判断其是否已为空。为空直接跳出循环

代码实现：

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

164 / 164 test cases passed.
Status: Accepted
Runtime: 1 ms