第19题 Remove Nth Node From End of List

Given a linked list, remove the nth node from the end of list and return its head.

For example,

   Given linked list: 1->2->3->4->5, and n = 2.   After removing the second node from the end, the linked list becomes 1->2->3->5.

Note:
Given n will always be valid.

Try to do this in one pass.

Solution：

/** * Definition for singly-linked list. * public class ListNode { *     int val; *     ListNode next; *     ListNode(int x) { *         val = x; *         next = null; *     } * } */public class Solution {    public ListNode removeNthFromEnd(ListNode head, int n) {        ListNode fakeHead = new ListNode(0);        fakeHead.next =head;        ListNode first =fakeHead, second =fakeHead;        for(int i=0; i<n; i++){            second=second.next;        }        while(second.next!=null){            first=first.next; second=second.next;        }        first.next=first.next.next;        return fakeHead.next;    }}