LeetCode 83 Remove Duplicates from Sorted List (链表)

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.

题目分析：两个指针O(n)扫一下

/** * 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 || head.next == null) {            return head;        }        ListNode cur = head;        ListNode nxt = head.next;        while (nxt != null) {            while (nxt != null && cur.val == nxt.val) {                nxt = nxt.next;            }            if (nxt != null) {                cur.next = nxt;                cur = nxt;                nxt = nxt.next;            }            cur.next = null;        }        return head;    }}

更简单的实现方式：

/** * 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) {        ListNode cur = head;        while (cur != null) {            if (cur.next == null) {                return head;            }            if (cur.val == cur.next.val) {                cur.next = cur.next.next;            } else {                cur = cur.next;            }        }        return head;    }}