1001 A+B Format

1.原题

1001 A+B Format

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

2.源代码

#include<iostream>
#include<stack>
using namespace std;
int main()
{
  stack<int> m;
  int a,b,sum;
  cin>>a>>b;
  sum=a+b;
  if(a+b<0)
  {
    cout<<'-';
    sum=-sum;
  }
  if(sum==0)m.push(0);
  while(sum!=0)
  {
    m.push(sum%10);
    sum/=10;
  }
  int sna=1;
  switch(m.size()%3)
  {
    case 1:sna=3;break;
    case 2:sna=2;break;
  }
  while(!m.empty())
  {
    cout<<m.top();
    m.pop();
    sna++;
    if(sna==4)
    {
      if(!m.empty())cout<<",";
      sna=1;
    }
  }
  return 0;
}

第一次写博客，来个题熟悉下操作。