[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;
        }
    }
};