leetcode Add Two Numbers c#版本

You are given two non-empty linked lists representing two non-negative integers. 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.

You may assume the two numbers do not contain any leading zero, except the number 0 itself.

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

话不多说，直接上代码

  1 using System;
  2 using System.Collections.Generic;
  3 using System.Linq;
  4 using System.Text;
  5 using System.Threading.Tasks;
  6 
  7 namespace ConsoleApplication2
  8 {
  9      public class ListNode {
 10      public int val;
 11      public ListNode next;
 12      public ListNode(int x) { val = x; }
 13  }
 14 
 15 
 16     public class Solution
 17     {
 18         public Solution()
 19         {
 20         }
 21 
 22         public ListNode AddTwoNumbers(ListNode l1, ListNode l2)
 23         {
 24             ListNode rev1 = ReverseList(l1);
 25             ListNode rev2 = ReverseList(l2);
 26             ListNode head, last;
 27             ListNode param1, param2;
 28             param1 = rev1;
 29             param2 = rev2;
 30             head = last = null;
 31             while (param1 != null || param2 != null)
 32             {
 33                 ListNode cur = new ListNode(0);
 34                 if (param1 != null)
 35                 {
 36                     cur.val += param1.val;
 37                     param1 = param1.next;
 38                 }
 39                 if (param2 != null)
 40                 {
 41                     cur.val += param2.val;
 42                     param2 = param2.next;
 43                 }
 44                 if (last == null)
 45                 {
 46                     last = head = cur;
 47                 }
 48                 else
 49                 {
 50                     last.next = cur;
 51                     last = cur;
 52                 }
 53             }
 54             ListNode ret = ReverseList(head);
 55             return ret;
 56         }
 57         ListNode ReverseList(ListNode ori)
 58         {
 59             ListNode cur, next, afterNext, ret;
 60             ret = null;
 61             cur = ori;
 62             next = cur.next;
 63             afterNext = null;
 64             while (true)
 65             {
 66                 if (GetNextTwo(cur, ref next, ref afterNext))
 67                 {
 68                     next.next = cur;
 69                     cur = next;
 70 
 71                     next = afterNext;
 72                     afterNext = next.next;
 73 
 74                 }
 75                 else
 76                 {
 77                     if (next == null)
 78                     {
 79                         break;
 80                     }
 81                     else if (afterNext == null)
 82                     {
 83                         next.next = cur;
 84                         ret = next;
 85                         break;
 86                     }
 87                 }
 88             }
 89             ori.next = null;
 90             return ret;
 91         }
 92         bool GetNextTwo(ListNode head, ref ListNode next, ref ListNode afterNext)
 93         {
 94             bool haveNextTwo = false;
 95             if (null == next && null != head.next)
 96             {
 97                 next = head.next;
 98             }
 99             if (null != next.next)
100             {
101                 afterNext = next.next;
102                 haveNextTwo = true;
103             }
104             return haveNextTwo;
105         }
106     }
107 
108 }

leetcode Add Two Numbers c#版本

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