示例:
输入: 1->2->6->3->4->5->6, val = 6
输出: 1->2->3->4->5
/**
* Definition for singly-linked list.
* function ListNode(val) {
* this.val = val;
* this.next = null;
* }
*/
/**
* @param {ListNode} head
* @param {number} val
* @return {ListNode}
*/
// 80ms 37mb
var removeElements = function(head, val) {
let newNode = new ListNode(), preNode = newNode, curNode = head
newNode.next = head
while(curNode){
if(curNode.val === val){
preNode.next = curNode.next
curNode = preNode.next
}else{
preNode = curNode
curNode = curNode.next
}
}
return newNode.next
};