题目链接

23. 合并K个升序链表

思路

把全部结点放入优先队列中，然后再依次组成新链表

代码

class Solution {
    public ListNode mergeKLists(ListNode[] lists) {
        PriorityQueue<Integer> listNodePriorityQueue = new PriorityQueue<>();
        for(int i = 0; i < lists.length; i++){
            ListNode p = lists[i];
            while(p != null){
                listNodePriorityQueue.add(p.val);
                p = p.next;
            }
        }

        ListNode res = new ListNode();
        ListNode tail = res;
        while(!listNodePriorityQueue.isEmpty()){
            tail.next = new ListNode(listNodePriorityQueue.poll());
            tail = tail.next;
        }

        return res.next;
    }
}