B # 0
I # 1
G # 1

(i) Function 1 is the 'destructor'.
It is executed automatically when an object of the class TestMeOut goes out of scope.
(ii) Function 2 is called default 'constructor'.
It is executed automatically when instance of the class TestMeOut comes into scope or when objects of the class TestMeOut are created.

When constructor and destructor are declared under public:
1. we can initialize the object while declaring it.
2. we can explicitly call the constructor.
3. we can overload constructors and therefore use multiple constructors to initialize objects automatically.
4. we can destroy the objects at the end of the class scope automatically (free unused memory). 
However, some C++ compilers and Dev C++ do not allow to declare constructor and destructors under private section. So it is better to declare constructor and destructor under public section only.

When the initial values are provided during runtime then it is called dynamic initialization.
Example to illustrate dynamic initialization
#include < iostream >
using namespace std;
class X
{
int n;
float avg;
public;
X(int p,float q)
{
n=p;
avg=q;
}
void disp( )
{
cout << "\n Roll number:-"<< n;
cout << "\nAverage:-"<< avg;
}
};
int main( )
{
int a; float b;
cout<< "\nEnter the Roll number";
cin >> a;
cout << "\nEnter the Average";
cin >> b;
X x(a,b);\\dynamic initialization
x.disp( );
return 0;
}
Output:
Enter the Roll Number 1201
Enter the Average 98.6
Roll number:- 1201
Average:- 98.6