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.
解答:
这是二刷时做的解法,比第一次刷时简单了很多。由于第一次刷时没有写这篇博客,现在补写一下。
/**
* Definition for singly-linked list.
* struct ListNode {
* int val;
* ListNode *next;
* ListNode(int x) : val(x), next(NULL) {}
* };
*/
class Solution {
public:
ListNode* deleteDuplicates(ListNode* head) {
if(!head) return head;
ListNode* pre=head;
ListNode* after=pre->next;
while(after!=NULL)
{
while(after!=NULL)
{
if(after->val==pre->val)
after=after->next;
else
break;
}
pre->next=after;
pre=after;
}
return head;
}
};