【Leetcode-Easy-21】Merge Two Sorted Lists

题目

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.

思路

巧用头结点（哑结点）

程序

/** * Definition for singly-linked list. * public class ListNode { *     int val; *     ListNode next; *     ListNode(int x) { val = x; } * } */class Solution {    public ListNode mergeTwoLists(ListNode l1, ListNode l2) {        ListNode dummyHead = new ListNode(0);        ListNode currNode = dummyHead;        while (l1 != null && l2 != null){            if (l1.val < l2.val){                currNode.next = l1;                l1 = l1.next;            }else{                currNode.next = l2;                l2 = l2.next;            }            currNode = currNode.next;        }        if (l1 != null) currNode.next = l1;        if (l2 != null) currNode.next = l2;        return dummyHead.next;    }}

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声明：题目来自Leetcode.