PAT1001---A+B Formatb

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

本题很简单，输入两个数后计算得出结果。要将其每三位输出，可以考虑转换为char类型，然后每3位添加一个分隔符','。可以用一个vector<char>来存储，然后从后往前输出即可。注意点是当为负数时将其转换为正数，最后再添加符号。代码如下：

#include<iostream>
#include<string>
#include<vector>
using namespace std;
int main()
{
	int A, B;
	cin >> A >> B;
	int result;
	result = A + B;
	bool flag = false;
	if (result < 0)
	{
		result = -result;
		flag = true;
	}
	vector<char> save;
	const int divider = 10;
	const char g = ',';
	int temp;
	int count = 0;
	if (result == 0)
		cout << 0;
	while (result != 0)
	{
		temp = result%divider;
		temp = temp + '0' - 0;
		save.push_back(temp);
		count++;
		result /= divider;//此处先计算result,可以避免只有3位数的情况
		if (count % 3 == 0 && count !=0 && result)
			save.push_back(g);
	}
	vector<char>::iterator ptr = save.end();
	if (flag)
		cout << '-';
	while (ptr != save.begin())
	{
		ptr--;//注意此处，因为save.end()为末尾元素的下一个位置，所以应该先进行减操作
		cout << *ptr;
	}
	cout << endl;
	return 0;
}