Leetcode-Remove Duplicates from Sorted List
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
.
Solution:
1 /** 2 * Definition for singly-linked list. 3 * public class ListNode { 4 * int val; 5 * ListNode next; 6 * ListNode(int x) { 7 * val = x; 8 * next = null; 9 * } 10 * } 11 */ 12 public class Solution { 13 public ListNode deleteDuplicates(ListNode head) { 14 if (head==null || head.next==null) return head; 15 ListNode preHead = new ListNode(-1); 16 preHead.next = head; 17 ListNode cur = head; 18 ListNode pre = preHead; 19 20 while (cur.next!=null){ 21 if (cur.val==cur.next.val){ 22 while (cur.val==cur.next.val){ 23 cur.next = cur.next.next; 24 if (cur.next==null) 25 break; 26 } 27 } else { 28 pre = cur; 29 cur = cur.next; 30 } 31 } 32 33 return preHead.next; 34 35 } 36 }