0%

删除链表中重复的结点

发表于 更新于

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

判重、全删

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
/*
struct ListNode {
    int val;
    struct ListNode *next;
    ListNode(int x) :
        val(x), next(NULL) {
    }
};
*/
class Solution {
public:
    ListNode* deleteDuplication(ListNode* pHead)
    {
        if (pHead == nullptr || pHead->next == nullptr)
        {
            return pHead;
        }
        else
        {
            ListNode head(pHead->val - 1);
            head.next = pHead;
            ListNode *last = &head, *current = head.next;
            while (current != nullptr)
            {
                if (current->next != nullptr &&current->val == current->next->val)
                {
                    while (current->next != nullptr && current->val == current->next->val)
                    {
                        ListNode *tail = current->next->next;
                        // delete current->next;
                        current->next = tail;
                    }
                    current = current->next;
                    // delete current
                    last->next = current;
                }
                else
                {
                    last = current;
                    current = current->next;
                }
            }
            return head.next;
        }
    }
};