// @Title: 训练计划 II (训练计划 II)
// @Author: qisiii
// @Date: 2022-02-20 17:58:45
// @Runtime: 0 ms
// @Memory: 39.2 MB
// @comment: 暴力
// @flag: BLUE
/**
 * 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 temp=head;
        int count=0;
        while(temp!=null){
            count++;
            temp=temp.next;
        }
        while(count!=k){
            count--;
            head=head.next;
        }
        return head;
    }
}

// @Title: 训练计划 II (训练计划 II)
// @Author: qisiii
// @Date: 2022-02-20 18:21:25
// @Runtime: 0 ms
// @Memory: 39.2 MB
// @comment: 快慢指针
// @flag: GREEN
/**
 * 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 slow=head;
        while(slow!=null&&k>0){
            k--;
            slow=slow.next;
        }
        ListNode fast=slow;
        while(fast!=null){
            head=head.next;
            fast=fast.next;
        }
        return head;
    }
}