链表逆序(JavaScript版)

 1 function reverseLinkedList(head) {
 2 
 3     if (head === null || head.next === null) {
 4         return head;
 5     }
 6     let newHead = null 
 7     while (head) {
 8         let next = head.next
 9         head.next = newHead
10         newHead = head
11         head = next
12     }
13     return newHead
14 }