2 Add Two Numbers LeeCode

Posted 2022-12-13 洽洽老大

Question: You are given two linked lists representing two non-negative numbers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the two numbers and return it as a linked list.

Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)
Output: 7 -> 0 -> 8

给定两个逆序列表，返回两个相加的结果，注意处理进位

public class Solution 

    public ListNode addTwoNumbers(ListNode l1, ListNode l2) 
       ListNode result = new ListNode(0);
       ListNode tt = result;
       int up = 0;//进位

       while(l1!=null || l2!=null)
           int m =0,n = 0;
           if(l1!=null) m = l1.val;l1 = l1.next;
           if(l2!=null) n = l2.val;l2 = l2.next;
           int a = m+n+up;
           tt.next = new ListNode(a%10);
           tt = tt.next;
           up = a/10;

       
       if(up ==1)
           tt.next = new ListNode(1);
       
       return result.next;