题解 | #又一版 A+B#

#include <functional>
#include <iostream>
#include <string>
#include <vector>
#include "cmath"
using namespace std;
int Chartoint(string n)
{
    int sum = 0;
    for (int i = 0; i < n.size(); i++)
    {
        sum = sum + (n[i]-'0') * pow(10, n.size() - i - 1);
    }
    return sum;
}
string add(string a, string b)
{
    float alast, blast;
    int la = a.size(), lb = b.size();
    int i = 0, j = 0, s = 0;
    int ra, rb;
    int wei = 0;
    int he = 0;
    string sum;
    ra = Chartoint(a);
    rb = Chartoint(b);
    if (a.size() >= b.size())
    {
        while (lb)
        {
            alast = (a[--la] - '0');
            ra = ra / pow(10, i++);
            blast = (b[--lb] - '0');
            rb = rb / pow(10, j++);
            he = alast + blast + wei;
            wei = 0;
            if (he >= 10)
            {
                wei = 1;
                he = he % 10;
            }
            a[la] = he+'0';
        }
        
        while (wei == 1)
         {
            la--;
            
            if ((a[la] - '0' + wei < 9))
            {
                a[la] = a[la] + 1;
                wei = 0;
            }
            else
            {
                a[la] = '0';
                wei = 1;
               
            }
         }
        
         if (la == 0&&wei==1)
         {
             a = "1" + a;
         }
        return a;
    }
    else {
        while (la)
        {
            alast = (a[--la] - '0');
            ra = ra / pow(10, i++);
            blast = (b[--lb] - '0');
            rb = rb / pow(10, j++);
            he = alast + blast + wei;
            wei = 0;
            if (he >= 10)
            {
                wei = 1;
                he = he % 10;
            }
            b[lb] = he + '0';
        }
      
        
        
            while(wei==1 )
            {
                lb--;
                if ((b[lb] - '0' + wei < 9))
                {
                    b[lb] = b[lb] + 1;
                    wei = 0;
                }
                else
                {
                    b[lb] = '0';
                    wei = 1;
                  
                }

            }
        
      
        if (lb == 0&& wei == 1)
        {
            b = "1" + b;
        }
        return b;

    }
}
string Divide(string str, int x)
{
    int re = 0;
    for (int i = 0; i < str.size(); i++)
    {
        int current = re * 10 + str[i] - '0';
        str[i] = current / x + '0';
        re = current % x;
    }
    int pos = 0;
    while (str[pos] == '0')
    {
        pos++;
    }
    return str.substr(pos);
}
int main() {
    string a, b;
    int m;
    int i;
    vector<float> answer;
    cin >> m;
    cin >> a >> b;
    if (a == "0" && b == "0")
    {
        cout << "0";
    }
    else
    {
        string sum = add(a, b);
        long long int nsum = 0;
        for (i = 0; i < sum.size(); i++)
        {
            nsum = (sum[i]-'0') * pow(10, sum.size() - i - 1) + nsum;
        }

        while (nsum!= 0)
        {
            answer.push_back(nsum % m);
            nsum = nsum / m;
        }
        for (i = answer.size() - 1; i >= 0; i--)
        {
            cout << answer[i];
        }
    }
}
// 64 位输出请用 printf("%lld")