IT公司100题-12-求1+2+…+n

 1 // 12.cc
 2 #include <iostream>
 3 using namespace std;
 4 
 5 class Object {
 6 public:
 7     Object() {
 8         ++N;
 9         Sum += N;
10     }
11     static void reset() { N = 0; Sum = 0; }
12     static int get_sum() { return Sum; }
13 
14 private:
15     static int N;
16     static int Sum;
17 };
18 
19 int Object::N = 0;
20 int Object::Sum = 0;
21 
22 int sum(int n) {
23     Object::reset();
24 
25     Object* a = new Object[n];
26 
27     delete []a;
28     a = 0;
29 
30     return Object::get_sum();
31 }
32 
33 int main() {
34     int n = 10;
35     cout << "The sum is: " << sum(n) << endl;
36     return 0;
37 }