[leetcode] day97 remove linked list elements

subject

203. Remove linked list elements 【 Simple 】

Answer key

Iterative solution

class Solution {
    
    public ListNode removeElements(ListNode head, int val) {
    
        ListNode newHead=new ListNode(0,head);
        ListNode p=newHead;
        while(p.next!=null){
    
            if(p.next.val==val)
                p.next=p.next.next;
            else
                p=p.next;
        }
        return newHead.next;
    }
}

Time complexity ：$O(n)$

Spatial complexity ：$O(1)$