206. Reverse Linked List#

 1public ListNode reverseList(ListNode head) {
 2  ListNode newHead = null;
 3
 4  while (head != null) {
 5    ListNode next = head.next;
 6    head.next = newHead;
 7    newHead = head;
 8    head = next;
 9  }
10
11  return newHead;
12}