题解 | #合并k个已排序的链表#
合并k个已排序的链表
https://www.nowcoder.com/practice/65cfde9e5b9b4cf2b6bafa5f3ef33fa6
import java.util.*; /* * public class ListNode { * int val; * ListNode next = null; * public ListNode(int val) { * this.val = val; * } * } */ public class Solution { /** * 代码中的类名、方法名、参数名已经指定,请勿修改,直接返回方法规定的值即可 * * * @param lists ListNode类ArrayList * @return ListNode类 */ public ListNode mergeKLists (ArrayList<ListNode> lists) { if (lists.isEmpty()){ return null; } ArrayList<Integer> data = new ArrayList<>(); for (ListNode listNode : lists) { countList(listNode,data); } if (data.size() < 1){ return null; } Integer[] datas = data.toArray(new Integer[data.size()]); Arrays.sort(datas); ListNode result = new ListNode(datas[0]); ListNode preNode = null; for (int i = 1; i < datas.length; i++) { ListNode temp = new ListNode(datas[i]); if (i == 1){ result.next = temp; preNode = temp; }else { preNode.next = temp; preNode = temp; } } return result; } public void countList(ListNode listNode,ArrayList<Integer> data){ while (listNode != null){ data.add(listNode.val); listNode = listNode.next; } } }