题目1001 A+B Format

记录学习写博客的第一天（PAT题目）

题目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 Specification:

Each input file contains one test case. Each case contains a pair of integers a and b where −1e6≤a,b≤1e6. 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

题解：

        题目大意是进行a+b结果的输出，不过对于结果的输出有一定的格式要求，我们进行特定格式输出即可。

对于计算的结果我们通过C++11中的to_string方法，将计算结果转化为字符串形式，然后依次输出字符，在下标不等于len - 1且满足(i + 1) % 3 == len % 3 时，进行"," 的输出,对于-号直接输出！这道题属于细节题目，要看清样例输出的结果格式，进行特定输出就行啦！

附上C++源代码：

#include 
#include 
using namespace std;

int main()
{
    int a,b;
    cin >> a >> b;
    string s = to_string(a + b);
    int len = s.length();
    for(int i = 0; i < len; i ++)
    {
        cout << s[i];
        if(s[i] == '-') continue;
        if(i != len - 1 && (i + 1) % 3 == len % 3)
        {
        	cout << ",";
        }
    }
    return 0;
}

This is my first blog~    I will try my best!