运行下列代码，屏幕上输出
#include <iostream>
using namespace std;
class my_class {
public:
static int count;
my_class() {
count++;
}
~my_class() {
count--;
}
static void print_count() {
cout << count << " ";
}
};
int my_class::count = 0;
int main() {
my_class obj1;
my_class::print_count();
my_class obj2;
obj2.print_count();
my_class obj3;
obj3.print_count();
return 0;
}
