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) {
        // write code here
        if(pHead1==null && pHead2==null) return null;
        else if(pHead1==null) return pHead2;
        else if(pHead2==null) return pHead1;
        
        if(pHead1.val<=pHead2.val){
        pHead1.next=Merge(pHead1.next,pHead2);
        return pHead1;
        }else{
            pHead2.next=Merge(pHead1,pHead2.next);
            return pHead2;
        }

    }
}