题解 | #合并两个排序的链表#

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 pHead1 ListNode类 
     * @param pHead2 ListNode类 
     * @return ListNode类
     */
    public ListNode Merge (ListNode pHead1, ListNode pHead2) {
        ArrayList<Integer> list = new ArrayList<>();
        //当链表的长度为null时
        if(pHead1 == null && pHead2 == null){
            return null;
        }
        //链表不为null时，将链表数据存入到list中
        while(pHead1 != null){
            list.add(pHead1.val);
            pHead1 = pHead1.next;
        }
        while(pHead2 != null){
            list.add(pHead2.val);
            pHead2 = pHead2.next;
        }
        //对list进行排序
        Collections.sort(list);
        //将list转换为链表并返回
        ListNode newNode = new ListNode(list.get(0));
        ListNode cur = newNode;
        for(int i = 1; i < list.size(); i++){
            cur.next = new ListNode(list.get(i));
            cur = cur.next;
        }
        return newNode;
    }
}