PAT 1001. A+B Format (20)

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

题目分析：

考查基本的数字变为字符串的操作；

实现方法：

计算结果由数字转为字符串存储，按位读取及显示；

#include "stdafx.h"

#include <stdio.h>
int main()
{
	int a, b, c;
	scanf("%d %d", &a, &b);

	c = a + b;

	if (c < 0)
	{
		printf("-");
		c *= (-1);
	}

	int count = 0;
	int tmp = c;
	char t[10];
	//for (i = 0;i)
	while(tmp!=0)
	{
		//count++;
		t[count++] = tmp %10 + '0';
		tmp = tmp / 10;
	}

	int sep = count /3;
	int LastNum = count % 3;

	int num = 0;

	if (LastNum == 0)
	{
		sep--;
	}

	if (sep < 0)
	{
		printf("0");
		return 0;
	}

	num = count - sep * 3;

	for (int i = 0;i<num;i++)
	{
		printf("%d", t[count - i - 1] - '0');
	}

	for ( int i = 0;i<sep;i++)
	{
		printf(",");
		for (int j = 0;j<3;j++)
		{
			printf("%d", t[count - num - 1] - '0');
			num++;
		}
	
	}



	return 0;
}