經(jīng)典雙指針阵苇，快指針先走k步垮抗，然后快慢指針一起走到最后。
/**
?*?Definition?for?singly-linked?list.
?*?public?class?ListNode?{
?*?????int?val;
?*?????ListNode?next;
?*?????ListNode(int?x)?{?val?=?x;?}
?*?}
?*/
class?Solution?{
????public?ListNode?getKthFromEnd(ListNode?head,?int?k)?{
????????ListNode?L?=?head;
????????ListNode?R?=?head;
????????for?(int?i?=?0;?i?<?k;?i++)?{
????????????R?=?R.next;
????????}
????????while?(R?!=?null)?{
????????????R?=?R.next;
????????????L?=?L.next;
????????}
????????return?L;
????}
}
