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.
/**
* 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 == NULL) return NULL;
ListNode *cur = head;
ListNode *next = head->next;
while(next != NULL)
{
if(next->val == cur->val)
{
cur->next = next->next;
delete next;
next = cur->next;
}
else
{
cur = cur->next;
next = next->next;
}
}
return head;
}
};