Given a sorted linked list, delete all duplicates such that each element appear only once.
Example 1:
Input: 1->1->2 Output: 1->2
Example 2:
Input: 1->1->2->3->3 Output: 1->2->3
my code:
/**
* 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* dummy = new ListNode(0);
dummy->next = head;
ListNode* p = dummy;
while (p->next != NULL && p->next->next != NULL) {
int sameNum = p->next->val;
p = p->next;
while (p->next!= NULL && p->next->val == sameNum) {
if (p->next->next != NULL)
p->next = p->next->next;
else
p->next = NULL;
}
}
return dummy->next;
}
};
Runtime: 12 ms, faster than 36.37% of C++ online submissions for Remove Duplicates from Sorted List.