剑指offer-题57：删除链表中重复的结点

今天药忘吃喽~ 2022-05-26 00:53 180阅读 0赞

## **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

实验平台：[牛客网][Link 1]

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## **解决思路：** ##

![这里写图片描述][70]  
![这里写图片描述][70 1]

java:

/*
     public class ListNode {
        int val;
        ListNode next = null;
    
        ListNode(int val) {
            this.val = val;
        }
    }
    */
    public class Solution {
        public ListNode deleteDuplication(ListNode pHead){
            if (pHead == null) {
                return null;
            }
            ListNode node = pHead;
            ListNode preNode = null;
            ListNode nextNode = null;
            while (node != null) {
                nextNode = node.next;
                boolean needDelete = false;
                if (nextNode != null && nextNode.val == node.val) {
                    needDelete = true;
                }
                if (!needDelete) {
                    preNode = node;
                    node = nextNode;
                }else{
                    int value = node.val;
                    ListNode deleteNode = node;
                    while (deleteNode != null && deleteNode.val == value) {
                        nextNode = deleteNode.next;
                        deleteNode = null;
                        deleteNode = nextNode;
                    }
                    if(preNode == null){
                        pHead = nextNode;
                    }else{
                        preNode.next = nextNode;
                    }
                    node = nextNode;
                }
            }
            return pHead;
        }
    }

python:

[Link 1]: https://www.nowcoder.com/ta/coding-interviews?page=1
[70]: /images/20220526/9a920cebcdbb4d57b1d90fcc2e0d9417.png
[70 1]: /images/20220526/3564aaf5aee843ac9c145a8e80d28cff.png