Title description

Give you the head node of the linked list head and an integer val, please delete all the nodes in the linked list that satisfy Node.val == val, and returns the new head node .

Solution ideas

• Because the element to be deleted may be at the head of the linked list, it is necessary to add a virtual node to the head in front of the head of the linked list

Input and output example

Code

/*** 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(-1,head);ListNode pre = dummy;ListNode cur = head;while(cur != null){if(cur.val == val){pre.next = cur.next;}else{pre = cur;}cur = cur.next;}return dummy.next;}}