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 −106≤a,b≤106. 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
翻译:输入a,b,范围都在正负10^6内,计算a + b,并且用标准格式输出,即,每隔三位输出一个逗号。
#include <iostream>
#include <string>
#include <cmath>
#include <algorithm>
using namespace std;
int main(){
int a,b,c;
string ans = "";
cin>>a>>b;
c = a + b;
if(c < 0){
cout<<"-";
c = c + 2*abs(c);
}
if(c == 0){cout<<"0"<<endl; return 0;}
while(c > 0){
int t = c % 10;
ans += (char)t + '0';
c = c / 10;
}
reverse(ans.begin(),ans.end());
int len = ans.length();
for(int i = len - 1; i >= 0; i--){
if((i + 1) % 3 == 0 && (i + 1) != len) cout<<",";
cout<<ans[len - i - 1];
}
return 0;
}