【leetcode】19. 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.

需要考虑的特殊情况是n和长度相同的时候。

/**
* Definition for singly-linked list.
* function ListNode(val) {
*     this.val = val;
*     this.next = null;
* }
*/
/**
* @param {ListNode} head
* @param {number} n
* @return {ListNode}
*/
var removeNthFromEnd = function(head, n) {
var ll = 0;
var temp = head;
while(temp!==null){
temp = temp.next;
ll++;
}
var cc = ll-n;
if(cc===0){
return head.next;
}
temp = head;
while(--cc){
temp = temp.next;
}

temp.next = temp.next.next;
return head;
};