19.Remove Nth Node From End of List

好吧，参考的答案…感觉这种思路棒棒的…and以后要用java…

public class Solution {    public ListNode removeNthFromEnd(ListNode head, int n) {        if(head==null) return null;        //定义两个指针，第一个保持指向最初的head指针        //使head指针移动，先到达访问第n个结点，第二个指针开始出发        //则当head访问完末尾结点时，第二个正好到达从后往前数的第n个结点        ListNode dummy = new ListNode(0);        dummy.next = head;        ListNode follower = dummy;        for(int i=0;i<n;i++){            if(head==null) return null;            head = head.next;        }        while(head!=null){            head = head.next;            follower = follower.next;        }        follower.next = follower.next.next;        return dummy.next;    }}