LeetCode:Remove Nth Node From End of List

题目链接：https://leetcode.com/problems/remove-nth-node-from-end-of-list/description/

题目介绍：删除链表倒数第n个结点

解题思路：先遍历一边链表得出该链表的长度，然后计算倒数第n个结点前的结点个数，然后删除链表倒数第n个结点。

代码如下：

class Solution {
public:
ListNode* removeNthFromEnd(ListNode* head, int n) {
int len = 0;
ListNode* node = head;
while (node != NULL) {
node = node->next;
len++;
}
int f = len-n-1;
if (f < 0) {
head = head->next;
} else {
ListNode* a = head;
while (f > 0) {
a = a->next;
f--;
}
a->next = a->next->next;
}
return head;
}
};