5.2.4.5 Remove Linked List Elements

一、题目

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

Example

Given 1->2->3->3->4->5->3, val = 3, you should return the list as 1->2->4->5

删除链表中等于给定值val的所有节点。

二、解题思路

删除链表中指定值，找到其前一个节点即可，将 next 指向下一个节点即可

三、解题代码

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

        return dummy.next;
    }
}