【leetcode阿里题库】21. Merge Two Sorted Lists

提交代码

class Solution {
    public ListNode mergeTwoLists(ListNode l1, ListNode l2) {
        if(l1==null&&l2==null)	return null;
        
        ListNode dummy=new ListNode(-1);
        ListNode p=dummy,p1=l1,p2=l2;
        while(p1!=null&&p2!=null) {
        	if(p1.val<p2.val) {
        		p.next=p1;
        		p1=p1.next;
        	}else {
        		p.next=p2;
        		p2=p2.next;
        	}
        	p=p.next;
        }
        if(p1!=null) 	p.next=p1;
        else	p.next=p2;
        return dummy.next;
    }
}

运行结果