Java 链表操作：从尾部开始查找第 k 个节点和构建链表

package CountDownListNode;public class CountDown {public class ListNode{int val;ListNode next;ListNode (int x){val = x;}}public ListNode getKthFromEnd(ListNode head , int k){ListNode front = head , behind = head;while(front != null && k>0){front = front.next;k--;}while(front !=null){front = front.next;behind = behind.next;}return behind;}public ListNode buildLinkedList(int[] nums){ListNode dummy = new ListNode(0);ListNode curr = dummy;for(int num : nums){ListNode newNode = new ListNode(num);curr.next = newNode;curr = curr.next;}return dummy.next;}}