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 9Sample Output
-999,991
题意:计算两个数的和,结果加千分符(,)分隔.
原以为要用字符串处理,后来一想,用递归就可以解决,万能的递归.
AC代码:
#include <iostream>
#include <cstdio>
using namespace std;
void fun(int x)
{
if(x/1000>0)
{
fun(x/1000);
printf(",%03d",x%1000);//不足三位添零补
}
else
{
cout<<x%1000;
}
}
int main()
{
int a,b;
while(cin>>a>>b)
{
int c=a+b;
if(c<0)
{
cout<<"-";
c=-c;
}
fun(c);
cout<<endl;
}
return 0;
}