PAT1001

初版

#include<iostream>
#include<string>
#include<sstream>

using namespace std;

int main()
{
    int i, j, sum;
    while(cin>>i>>j)
    {
        string out;
        stringstream ss;
        sum = i + j;
        ss<<sum;
        ss>>out;
        int len = out.length();
        int remain = len % 3;
        string _out;
        if(remain != 0)
        {
            for(int i = 0; i < remain; i++)
            {
                _out = _out + out[i];
            }
            if(len - remain != 0 && out[remain - 1] != '-')
            {
                _out += ',';
            }
        }
        int num = 0;
        for(int i = remain; i < len; i++)
        {
            if(num == 3)
            {
                _out += ',';
                num = 0;
            }
            _out += out[i];
            num++;
        }
        cout<<_out<<endl;
    }
    return 0;

修改版晚点给