PAT（甲级）练习

 1 #include<iostream>
 2 #include<stdio.h>
 3 #include<string>
 4 #include<string.h>
 5 #include<algorithm>
 6 #include<list>
 7 #include <sstream>
 8 #include<math.h>
 9 #include<vector>
10 #include<map>
11 #include<set>
12 using namespace std;
13 int main() {
14     int a, b; cin >> a >> b;
15     int sum = a + b;
16     string s = std::to_string(sum);
17     bool falg = false;
18     if (s[0] == ‘-‘)
19     {
20         falg = true;
21         s.erase(0, 1);
22     }
23     int count = 0;
24     for (int i=s.length()-1; i>=0; i--) {
25         if ( i-1 >= 0) {
26             count++;
27             if (count == 3) {
28                 s.insert(i, ",");
29                 count = 0;
30             }
31         }
32         else
33             break;
34     }
35     if (falg)
36         s.insert(0, "-");
37     cout << s;
38     system("pause");
39     return 0;
40 }