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 Specification:
Each input file contains one test case. Each case contains a pair of integers a and b where −10^6 ≤a,b≤ 10^6.The numbers are separated by a space.
Output Specification:
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
求两数之和，按照每三位一个逗号的格式进行输出。
题目分析
先计算两数之和，再转为字符串，然后按格式输出即可。
注意，从右到左每3位一个逗号，不要从左到右。
AC代码
#include <bits/stdc++.h>
using namespace std;
int main()
{
int a, b, len, i;
char s[20];
cin >> a >> b;
sprintf(s, "%d", a + b);
len = strlen(s);
for (i = 0; i < len; i++)
{
cout << s[i];
if ((len - 1 - i) % 3 == 0 && i != len - 1 && !(i == 0 && s[i] == '-'))
cout << ",";
}
return 0;
}