lc_top_0921

lc206 反转链表

class Solution {
    public ListNode reverseList(ListNode head) {
        ListNode prev = null;
        ListNode curr = head;
        while (curr != null) {
            ListNode next = curr.next;
            curr.next = prev;
            prev = curr; 
            curr = next;
        }
        return prev;
    }
}