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) {
ListNode* root = head;
if (head == NULL || head->next == NULL)
return root;
while (head->next != NULL)
{
if(head ->val ==head->next->val)
{head->next = head->next->next;
}
else head = head->next;
}
return root;
}
};