1001 A+B Format

最新推荐文章于 2022-10-04 11:44:07 发布

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本文介绍了一种算法，用于计算两个整数的和，并将结果转换为字符串，以便于按照标准格式进行输出。具体步骤包括求和、转换为字符串、按三位分组并插入逗号。

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

解题思路：

求和之后，将整形转变为 string 类型，再用其长度除 3 ，先输出余数长度的数字，然后每 3 位输出一个逗号，注意末尾无逗号（详见判断条件）；

#include <iostream>
#include <sstream>
#include <cstring>
#include <string>
using namespace std;

int main()
{
	int a, b;
	cin >> a >> b;
	int sum = a + b;
	if (sum < 0) {
		sum = -sum;
		cout << "-";
	}
	stringstream s;
	string num;
	s << sum;
	s >> num;
	int len = num.length();
	int temp = len % 3;
	for (int i = 0; i < len; i++) {
		if ((i == temp || (i-temp) % 3 == 0) && i != 0)
			cout << ",";
		cout << num[i];
	}
}