题目链接：https://pintia.cn/problem-sets/994805342720868352/problems/994805528788582400
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 −. 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
1 #include <iostream> 2 #include <cstdio> 3 #include <string> 4 #include <cstring> 5 #include <algorithm> 6 #include <stack> 7 using namespace std; 8 int main() 9 { 10 int n,m,sum; 11 while(cin>>n>>m){ 12 sum=n+m; 13 if(sum==0){ 14 cout<<0<<endl; 15 continue; 16 } 17 int flag=0; 18 if(sum<0){ 19 flag=1; 20 sum=-sum; 21 } 22 char c='-'; 23 stack<char> s; 24 int t=0; 25 while(sum){ 26 c=sum%10+'0'; 27 s.push(c); 28 t++; 29 if(t%3==0&&sum/10) s.push(','); 30 sum/=10; 31 } 32 if(flag) s.push('-'); 33 while(!s.empty()){ 34 cout<<s.top(); 35 s.pop(); 36 } 37 cout<<endl; 38 } 39 return 0; 40 }