问题描述:
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
源码:
维护三个指针
/*
struct ListNode {
int val;
struct ListNode *next;
ListNode(int x) :
val(x), next(NULL) {
}
};
*/
class Solution {
public:
ListNode* deleteDuplication(ListNode* pHead)
{
if(!pHead) return pHead;
ListNode *pre = nullptr, *cur = pHead, *nex = nullptr;
while(cur){
nex = cur->next;
if(nex && nex->val==cur->val){
while(nex->next && nex->next->val==cur->val) nex = nex->next;
if(cur==pHead) pHead = nex->next;
else pre->next = nex->next;
cur = nex->next;
}
else{
pre = cur;
cur = cur->next;
}
}
return pHead;
}
};