[剑指Offer] 56.删除链表中重复的结点

题目描述

在一个排序的链表中，存在重复的结点，请删除该链表中重复的结点，重复的结点不保留，返回链表头指针。 例如，链表1->2->3->3->4->4->5 处理后为 1->2->5

【思路】递归

 /*
 struct ListNode {
     int val;
     struct ListNode *next;
     ListNode(int x) :
         val(x), next(NULL) {
     }
 };
 */
 class Solution {
 public:
     ListNode* deleteDuplication(ListNode* pHead)
     {
         if((pHead == NULL)||(pHead != NULL && pHead->next == NULL))
             return pHead;
         ListNode* current;
         if(pHead->val == pHead->next->val){
             current = pHead->next->next;
             while(current != NULL && current->val == pHead->val)
                 current = current->next;
             return deleteDuplication(current);
         }else{
             current = pHead->next;
             pHead->next = deleteDuplication(current);
             return pHead;
         }
     }
 };