合并两个有序单链表——java实现

矫情吗；* 2024-03-17 10:31 21阅读 0赞

题目：  
将两个升序链表合并为一个新的 升序 链表并返回。新链表是通过拼接给定的两个链表的所有节点组成的。  
![在这里插入图片描述][5482e735460645a8b1d159b13d759825.png]  
![在这里插入图片描述][6b119c8a076f4d57b94a9bee9bf19d3f.png]  
原题OJ链接https://leetcode.cn/problems/merge-two-sorted-lists/description/

解答

/**
     * Definition for singly-linked list.
     * public class ListNode {
     *     int val;
     *     ListNode next;
     *     ListNode() {}
     *     ListNode(int val) { this.val = val; }
     *     ListNode(int val, ListNode next) { this.val = val; this.next = next; }
     * }
     */
    class Solution {
        
        public ListNode mergeTwoLists(ListNode list1, ListNode list2) {
        
            ListNode cur1 = list1;
            ListNode cur2 = list2;
            ListNode newhead = new ListNode(-1);
            ListNode pre = newhead;
            while(cur1 != null && cur2 != null ){
        
                if(cur1.val <= cur2.val ) {
        
                    pre.next = cur1;
                    pre = pre.next;
                    cur1 = cur1.next;
                }
                else{
        
                    pre.next = cur2;
                    pre = pre.next;
                    cur2 = cur2.next;
                }
            }
            if(cur1 != null){
        
                pre.next = cur1;
            }
            else{
        
                pre.next = cur2;
            }
            return newhead.next;
        }
    }

[5482e735460645a8b1d159b13d759825.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/17/17258fff652c42d888ff9abc61587d19.png
[6b119c8a076f4d57b94a9bee9bf19d3f.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/17/cc9be910d646404d8a7d2d4046c55ea4.png