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 {
    public ListNode Merge (ListNode head1, ListNode head2) {
        ListNode nweHead=new ListNode(-1);
        ListNode tmp=nweHead;
        
        while(head1!=null && head2!=null){
            if(head1.val<head2.val){
                tmp.next=head1;
                head1=head1.next;
                tmp=tmp.next;
            }else{
                tmp.next=head2;
                head2=head2.next;
                tmp=tmp.next;
            }
        }

        if(head1!=null){
            tmp.next=head1;
        }
        if(head2!=null){
            tmp.next=head2;
        }

        return nweHead.next;
        
    }
}