1001. A+B Format (20)

https://www.patest.cn/contests/pat-a-practise/1001

#include <cstdio>#include <iostream>#include <cmath>using namespace std;int main(){  int a, b,str[100],k = 0;  cin >> a >> b;  int sum = a + b;  if (sum == 0){    cout << 0 << endl;    return 0;  }  if (sum < 0) {    sum = -sum;    cout << "-";  }  if (sum == 0){    cout << 0 << endl;  }  else {    while (sum) {      int s1 = sum % 10;      sum = sum / 10;      str[k++] = s1;    }    for (int i = k-1; i >= 0; i--) {      cout << str[i];      if ((i) % 3 == 0 && i != 0) cout << ",";     }    cout << endl;  }  return 0;}