LeetCode 23 合并K个升序链表

Posted 2021-12-14 Starzkg

https://leetcode-cn.com/problems/merge-k-sorted-lists/

解决方案

import java.util.Comparator;
import java.util.PriorityQueue;

class Solution 
    public ListNode mergeKLists(ListNode[] lists) 
        if (lists.length == 0) 
            return null;
        
        ListNode head = new ListNode();
        ListNode p = head;
        PriorityQueue<ListNode> queue = new PriorityQueue<>(lists.length, Comparator.comparingInt(node -> node.val));
        for (ListNode node : lists) 
            if (node != null) 
                queue.add(node);
            
        
        while (queue.size() > 0) 
            ListNode node = queue.poll();
            p.next = node;
            p = node;
            if (node.next != null) 
                node = node.next;
                queue.add(node);
            

        
        return head.next;