203. 移除鏈表元素 - 力扣（LeetCode） (leetcode-cn.com)

/**
 * 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 null;
        ListNode pre = new ListNode(-1);
        pre.next = head;
        ListNode cur = pre;
        while(cur.next!=null){
            if(cur.next.val==val){
                //刪除節點
                cur.next = cur.next.next;
            }else{
                cur = cur.next;
            }
        }
        return pre.next;
    }
}