Leetcode:反转链表

 1 public ListNode reverseList(ListNode head) {
 2     //尾节点
 3     ListNode prev = null;
 4     //头节点
 5     ListNode curr = head;
 6     while (curr != null) {
 7         //记录当前节点的尾节点
 8         ListNode nextTemp = curr.next;
 9         //修改当前节点尾节点为null,（1->null,2->1->null,3->2->1->null）
10         curr.next = prev;
11         //记录下一节点尾节点
12         prev = curr;
13         //记录下一节点头节点(原节点的尾节点)
14         curr = nextTemp;
15     }
16     return prev;
17 }