leetcode——83——Remove Duplicates from Sorted List

Given a sorted linked list, delete all duplicates such that each element appear onlyonce.

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