题目

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

Example:

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

题意

将给定链表中所有含有指定值的结点删除。

思路

注意需要连续删除结点的情况。

代码实现

Java

  1. /**
  2.  * Definition for singly-linked list.
  3.  * public class ListNode {
  4.  *     int val;
  5.  *     ListNode next;
  6.  *     ListNode(int x) { val = x; }
  7.  * }
  8.  */
  9. class Solution {
  10.     public ListNode removeElements(ListNode head, int val) {
  11.         ListNode dumb = new ListNode(0);
  12.         dumb.next = head;
  13.         ListNode pre = dumb;
  14.         ListNode cur = head;
  16.         while (cur != null) {
  17.             if (cur.val == val) {
  18.                 pre.next = cur.next;
  19.                 cur = cur.next;
  20.             } else {
  21.                 pre = pre.next;
  22.                 cur = cur.next;
  23.             } 
  24.         }
  26.         return dumb.next;
  27.     }
  28. }

JavaScript

  1. /**
  2.  * @param {ListNode} head
  3.  * @param {number} val
  4.  * @return {ListNode}
  5.  */
  6. var removeElements = function (head, val) {
  7.   let dummy = new ListNode(0, head)
  8.   let pre = dummy
  9.   let cur = head
  10.   while (cur) {
  11.     if (cur.val === val) {
  12.       pre.next = cur.next
  13.     } else {
  14.       pre = cur
  15.     }
  16.     cur = cur.next
  17.   }
  18.   return dummy.next
  19. }