题目描述：给定两个链表，逆序表示两个整数，对这两个链表进行求和。

思路：注意进位即可，可以就地操作，但是实现稍微麻烦一点（如果不就地的话，可以转化成递归操作，代码更加简洁）

 

  1 #include <iostream>
  2 #include <string>
  3 #include <fstream>
  4 #include <map>
  5 #include <algorithm>
  6 #include <vector>
  7 #include <ctime>
  8 #include <bitset>
  9 
 10 using namespace std;
 11 
 12 template<typename T>
 13 class Node
 14 {
 15 public:
 16     Node<T> *next;
 17     T data;
 18 
 19     Node(T d):data(d),next(NULL){}
 20     void appendToTail(T d)
 21     {
 22         Node<T> *end = new Node<T>(d);
 23         Node<T> *n = this;
 24         while(n->next != NULL)
 25         {
 26             n = n->next;
 27         }
 28         n->next = end;
 29     }
 30 };
 31 
 32 int main()
 33 {
 34     Node<int> *head1 = new Node<int>(7);
 35     head1->appendToTail(1);
 36     head1->appendToTail(6);
 37     Node<int> *head2 = new Node<int>(5);
 38     head2->appendToTail(9);
 39     head2->appendToTail(2);
 40     //2.4
 41     int c = 0;
 42     Node<int> *resHead = NULL;
 43     if(head1 == NULL)
 44     {
 45         resHead = head1;
 46     }
 47     else if(head2 == NULL)
 48     {
 49         resHead = head2;
 50     }
 51     else
 52     {
 53         resHead = head1;
 54         Node<int> *restmp = head1;
 55         while(head1 != NULL && head2 != NULL)
 56         {
 57             int tmp1 = head1->data;
 58             int tmp2 = head2->data;
 59             restmp->data = (tmp1+tmp2+c)%10;
 60             c = (tmp1+tmp2)/10;
 61             head1 = head1->next;
 62             head2 = head2->next;
 63             if(head1 != NULL)
 64             {
 65                 restmp = restmp->next;
 66             }
 67             else
 68             {
 69                 restmp->next = head2;
 70                 if(head2 != NULL)
 71                     restmp = restmp->next;
 72             }
 73         }
 74         while(head1 != NULL)
 75         {
 76             int tmp1 = head1->data;
 77             restmp->data = (tmp1+c)%10;
 78             c = (head1->data+c)/10;
 79             head1 = head1->next;
 80             if(restmp->next != NULL)
 81                 restmp = restmp->next;
 82         }
 83         while(head2 != NULL)
 84         {
 85             int tmp2 = head2->data;
 86             restmp->data = (tmp2+c)%10;
 87             c = (tmp2+c)/10;
 88             head2 = head2->next;
 89             if(restmp->next != NULL)
 90                 restmp = restmp->next;
 91         }
 92         if(c != 0)
 93             restmp->next = new Node<int>(c);
 94     }
 95     while(resHead != NULL)
 96     {
 97         cout<<resHead->data<<endl;
 98         resHead = resHead->next;
 99     }
100     return 0;
101 }