leetcode：Remove Linked List Elements 【Java】

一、问题描述

Remove all elements from a linked list of integers that have value val.

Example
Given: 1 --> 2 --> 6 --> 3 --> 4 --> 5 --> 6, val = 6
Return: 1 --> 2 --> 3 --> 4 --> 5

二、问题分析

设置两个指针pre和cur。

三、算法代码

/** * Definition for singly-linked list. * public class ListNode { *     int val; *     ListNode next; *     ListNode(int x) { val = x; } * } */public class Solution {    public ListNode removeElements(ListNode head, int val) {        if(head == null){            return null;        }               while(head != null && head.val == val){            head = head.next;        }                    ListNode pre = head, cur = head;        while(cur != null){            if(cur.val == val){                pre.next = cur.next;            }else {                pre = cur;            }            cur = cur.next;        }        return head;    }}