LeetCode 021 Merge Two Sorted Lists

题目

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Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists.

把两个排序的链表合并起来。

思路

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1 合并排序的一部分，基础的基础。

2 当一个链表结束的时候，后续部分不要写错。

if(l1==null){
            cur3.next = l2; //不是l1

        }

代码

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public class Solution {
    public ListNode mergeTwoLists(ListNode l1, ListNode l2) {
        ListNode dummy = new ListNode(Integer.MIN_VALUE);
        ListNode cur3 = dummy;
        while(l1!=null && l2!=null){
            if(l1.val<l2.val){
                cur3.next = l1;
                cur3 = cur3.next;
                l1 = l1.next;
            }
            else{
                cur3.next = l2;
                cur3 = cur3.next;
                l2 = l2.next;
            }
        }
        if(l1==null){
            cur3.next = l2;
        }
        else{
            cur3.next = l1;
        }
        return dummy.next;
    }
}

&& 与 || 要注意