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Remove Nth Node From End of List

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.

 1 /** 2  * Definition for singly-linked list. 3  * public class ListNode { 4  *     int val; 5  *     ListNode next; 6  *     ListNode(int x) { 7  *         val = x; 8  *         next = null; 9  *     }10  * }11  */12 public class Solution {13     public ListNode removeNthFromEnd(ListNode head, int n) {14         List<ListNode> list = new ArrayList<ListNode>();15         ListNode temp = head;16         if(null == head.next)17             return null;18         while(null != temp){19             list.add(temp);20             temp = temp.next;21         }//只要一趟,把所有节点保存起来22         23         if(list.size() - n - 1 >= 0){24             temp = list.get(list.size() - n - 1);25             temp.next = temp.next.next;26             return head;27         }28         head = head.next;29         return head;30     }31 }

 ps:依然是双指针思想,两个指针相隔n-1,每次两个指针向后一步,当后面一个指针没有后继了,前面一个指针就是要删除的节点。博客园上面看到的,就没有实现了

Remove Nth Node From End of List