题解 | #反转链表#

/*
public class ListNode {
    int val;
    ListNode next = null;

    ListNode(int val) {
        this.val = val;
    }
}*/
public class Solution {
    public ListNode ReverseList(ListNode head) {
        ListNode newHead = new ListNode(-1);
        while(head != null) {
            ListNode current = head;
            head = head.next;
            current.next = newHead.next;
            newHead.next = current;
        }
        return newHead.next;
    }
}

通过头插法，实现链表反转。