1001. A+B Format

Calculate a + b and output the sum in standard format -- that is, the digits must be separated into groups of three by commas (unless there are less than four digits).

Input

Each input file contains one test case. Each case contains a pair of integers a and b where -1000000 <= a, b <= 1000000. The numbers are separated by a space.

Output

For each test case, you should output the sum of a and b in one line. The sum must be written in the standard format.

Sample Input

-1000000 9

Sample Output

-999,991

题目大意：

给出a和b，计算a+b并按照格式从后往前数每三位一个逗号的格式输出。

思路：

把数字转换成字符串处理。

AC代码：

#include <iostream>
#include <iomanip>
#include <stdio.h>
#include <stdlib.h>
#include <cmath>
#include <algorithm>
#include <cstring>
#include <cctype>
#include <sstream>
#include <map>
#include <set>
#include <vector>
#include <queue>
#include <stack>
using namespace std;

int main()
{
    int a,b,c,i,len;
    string num;
    stringstream ss;
    cin>>a>>b;
    c = a+b;
    if(c < 0)
    {
        cout<<"-";
        c = abs(c);
    }
    ss<<c;
    ss>>num;
    len = num.size();
    for(i=0;i<len;i++)
    {
        if((len-i)%3==0 && i!=0)
            cout<<",";
        cout<<num[i];
    }
    cout<<endl;
	return 0;
}