面试金典--对链表表示的整数求和

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）

#include <iostream>
#include <string>
#include <fstream>
#include <map>
#include <algorithm>
#include <vector>
#include <ctime>
#include <bitset>

using namespace std;

template<typename T>
class Node
{
public:
    Node<T> *next;
    T data;

    Node(T d):data(d),next(NULL){}
    void appendToTail(T d)
    {
        Node<T> *end = new Node<T>(d);
        Node<T> *n = this;
        while(n->next != NULL)
        {
            n = n->next;
        }
        n->next = end;
    }
};

int main()
{
    Node<int> *head1 = new Node<int>(7);
    head1->appendToTail(1);
    head1->appendToTail(6);
    Node<int> *head2 = new Node<int>(5);
    head2->appendToTail(9);
    head2->appendToTail(2);
    //2.4
    int c = 0;
    Node<int> *resHead = NULL;
    if(head1 == NULL)
    {
        resHead = head1;
    }
    else if(head2 == NULL)
    {
        resHead = head2;
    }
    else
    {
        resHead = head1;
        Node<int> *restmp = head1;
        while(head1 != NULL && head2 != NULL)
        {
            int tmp1 = head1->data;
            int tmp2 = head2->data;
            restmp->data = (tmp1+tmp2+c)%10;
            c = (tmp1+tmp2)/10;
            head1 = head1->next;
            head2 = head2->next;
            if(head1 != NULL)
            {
                restmp = restmp->next;
            }
            else
            {
                restmp->next = head2;
                if(head2 != NULL)
                    restmp = restmp->next;
            }
        }
        while(head1 != NULL)
        {
            int tmp1 = head1->data;
            restmp->data = (tmp1+c)%10;
            c = (head1->data+c)/10;
            head1 = head1->next;
            if(restmp->next != NULL)
                restmp = restmp->next;
        }
        while(head2 != NULL)
        {
            int tmp2 = head2->data;
            restmp->data = (tmp2+c)%10;
            c = (tmp2+c)/10;
            head2 = head2->next;
            if(restmp->next != NULL)
                restmp = restmp->next;
        }
        if(c != 0)
            restmp->next = new Node<int>(c);
    }
    while(resHead != NULL)
    {
        cout<<resHead->data<<endl;
        resHead = resHead->next;
    }
    return 0;
}