题解 | #合并k个已排序的链表#

//使用大根堆解决
	public ListNode mergeKLists(ArrayList<ListNode> lists) {
        PriorityQueue<Integer> pq = new PriorityQueue<>((x, y) -> y - x);
        ListNode head = new ListNode(-1);
        
        for (ListNode node : lists) {
            while(node != null) {
                pq.offer(node.val);
                node = node.next;
            }
        }
        
        while(!pq.isEmpty()) {
            ListNode newNode = new ListNode(pq.poll());
            newNode.next = head.next;
            head.next = newNode;
        }
        return head.next;
    }