Remove Duplicates from Sorted List

Desicription

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.

Solution

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/**
* 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* now = head;
while(now){
while(now->next && now->val == now->next->val){
ListNode* tmp = now->next;
now->next = tmp->next;
free(tmp);
}
now = now->next;
}
return head;
}
};