题解 | #单链表的排序 利用小根堆#

import java.util.*;

/*
 * public class ListNode {
 *   int val;
 *   ListNode next = null;
 * }
 */

public class Solution {
    /**
     * 
     * @param head ListNode类 the head node
     * @return ListNode类
     */
    public ListNode sortInList (ListNode head) {
        // write code here
        if (head == null){
            return head;
        }
        PriorityQueue<Integer> heap = new PriorityQueue<>();
        ListNode temp = head;
        while (temp != null){
            heap.offer(temp.val);
            temp = temp.next;
        }
        ListNode temp1 = head;
        while (temp1 != null){
            temp1.val = heap.poll();
            temp1 = temp1.next;
        }
        return head;
    }
}