遇到的问题:input{1,1,1}, output{1,1}, expected{1}, 原因在于若temp.val==temp.next.val, 则需要temp.next=temp.next.next, 这时候就不要temp=temp.next了
注意停止条件不光是temp!=null,还应该有temp.next!=null
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) return null; 15 ListNode temp=head; 16 while(temp!=null && temp.next!=null){ 17 if(temp.val==temp.next.val){ 18 temp.next=temp.next.next; 19 } 20 else temp=temp.next; 21 } 22 return head; 23 } 24 }
别人的solution:
Solution1: (未研究,感觉比我的复杂)
1 public class Solution { 2 public ListNode deleteDuplicates(ListNode head) { 3 // Start typing your Java solution below 4 // DO NOT write main() function 5 if(head == null) // we can otherwise use dummy node instead. But 6 return null; // be careful about the value you put in the dummy node. 7 8 ListNode currentNode = head; 9 while(currentNode.next!=null){ 10 ListNode p = currentNode.next; 11 while(p!=null && p.val==currentNode.val) 12 p = p.next; 13 if(p == null){ 14 currentNode.next =null; 15 break; 16 } 17 currentNode.next = p; 18 currentNode = p; 19 } 20 return head; 21 } 22 }
Solution 2: Runner Technique(未研究,感觉是好的切入点,但是比我的复杂)
1 public class RemoveDuplicatesFromSortedList { 2 public ListNode deleteDuplicates(ListNode head) { 3 // Start typing your Java solution below 4 // DO NOT write main() function 5 if (head == null) { 6 return null; 7 } 8 if (head.next == null) { 9 return head; 10 } 11 ListNode saveHead = head; 12 ListNode runner = head; 13 14 while (runner.next != null) { 15 if (runner.val != runner.next.val && runner.val != saveHead.val) { 16 head.next = new ListNode(runner.val); 17 head = head.next; 18 } 19 runner = runner.next; 20 } 21 if (runner.val != saveHead.val) { 22 head.next = new ListNode(runner.val); 23 head = head.next; 24 head.next = null; 25 } else { 26 head.next = null; 27 } 28 return saveHead; 29 30 } 31 }
Leetcode: Remove Duplicates from Sorted List,布布扣,bubuko.com
Leetcode: Remove Duplicates from Sorted List
原文:http://www.cnblogs.com/EdwardLiu/p/3704782.html