problem
1001 A+B Format (20分)
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
- 将两个数字相加，用标准格式输出最终结果
solution
- 两数相加开始还以为是高精度有点烦，结果1e6的数据怎么加都不会超过int的。
- 标准格式输出，想用string流但是不会（而且慢），想用除法和取模发现循环顺序不对，最后用了递归。（分三步优化）
- 提交WA了第四个点，考虑特殊数据 0 0时没有输出
#include<iostream>
using namespace std;
void output(int c, int cnt){
if(!c)return ;
if(cnt%3==0 && c/10!=0){
output(c/10,cnt+1);
cout<<",";
}else output(c/10,cnt+1);
cout<<c%10;
}
int main(){
int a, b;
cin>>a>>b;
int c = a+b;
if(c==0){
cout<<0<<endl;
return 0;
}
if(c<0){
cout<<"-";
c = -c;
}
output(c,1);
return 0;
}
