83. 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.

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

/**
* 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* tmp = head;
while(tmp != NULL && tmp->next != NULL){
if(tmp->val == tmp->next->val){
tmp->next = tmp->next->next;
} else
tmp = tmp->next;
}
return head;
}
};