1001. A+B Format (20)

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

Each input file contains one test case. Each case contains a pair of integers a and b where -1000000 <= a, b <= 1000000. The numbers are separated by a space.

Output

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

PAT的OJ服务器是64位的Linux，很多情况下都可不必担心int的溢出问题，可以不用考虑整型字符串加法的问题。

本题的难点在于分隔符添加的问题。

#include <iostream>#include <stack>#include <string>#include <cstdlib>using namespace std;int main(){long int a,b;long int sum;int minusflag = 0;stack<char> s;cin >> a >> b;sum = a + b;if(sum < 0) {minusflag = 1;sum = -sum;}int cnt = 0;if(sum == 0)s.push('0');while(sum != 0){s.push(sum % 10 + '0');cnt++;if(cnt == 3){s.push(',');cnt = 0;}sum /= 10;}if(s.top() == ',') s.pop();if(minusflag == 1)cout << '-';while(!s.empty()){char tmp = s.top();cout << tmp;s.pop();}system("pause");return 0;}