[刷题防痴呆] 0203 - 移除链表元素 (Remove Li

题目地址

https://leetcode.com/problems/remove-linked-list-elements/description/

题目描述

203. Remove Linked List Elements

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

Example:

Input:  1->2->6->3->4->5->6, val = 6
Output: 1->2->3->4->5

思路

• 如果当前位的下一位的val与所给val相等, 则跳过.

关键点

• 注意, 此题一开始要把head往前走一位, 因为要看下head是不是需要删除.

代码

• 语言支持：Java

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode() {}
 *     ListNode(int val) { this.val = val; }
 *     ListNode(int val, ListNode next) { this.val = val; this.next = next; }
 * }
 */
class Solution {
    public ListNode removeElements(ListNode head, int val) {
        if (head == null) {
            return head;
        }
        
        ListNode dummy = new ListNode(0);
        dummy.next = head;
        head = dummy;
        
        while (head.next != null) {
            if (head.next.val == val) {
                head.next = head.next.next;
            } else {
                head = head.next;
            }
        }
        
        return dummy.next;
    }
}