pat甲 1001.A+B Format

1001. A+B Format (20)

时间限制

400 ms

内存限制

65536 kB

代码长度限制

16000 B

判题程序

Standard

作者

CHEN, Yue

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

tips：1.pat不支持itoa函数，这里使用了sprintf代替，另外也可以自己写一个整数字符串转换函数

方法1：将整数转换为字符串处理

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

int a ,b;
int main()
{
	cin>>a>>b;
	int c=a+b;
	char s[100];
	if(c<0){cout<<"-";
	c=-c;
	}
	sprintf(s,"%d",c);
	
	string ss(s);
	for(int j=0;j<=ss.length()-1;j++)
	{
		cout<<ss[j];
		if((ss.length()-1-j)%3==0&&j!=ss.length()-1)cout<<",";
	}
	return 0;
}

方法二：递归

#include<iostream>

using namespace std;


void solve(int a)
{
	if(a/1000==0)//出口 
	{
		cout<<a;
		return ;
	}

	solve(a/1000); 
	printf(",%03d",a%1000);//回溯 
	
 } 

int main()
{
	int a,b;
	cin>>a>>b;
	int ans=a+b;
	if(ans<0)
	{
		cout<<"-";
		ans=-ans;
	}
	solve(ans);
	
 }