Конструктор и деструктор

#include <time>
class b
{
time_t timeAppStart;
time_t timeAppStop;
b()
{
time(&timeAppStart);
}
~b()
{
time(&timeAppStop);
}
}

#include <iostream>
#include <time.h>
#include <Windows.h>
using namespace std;
void main()
{    time_t t;
    time_t off;
    t = time(NULL);
    Sleep(3000);
    off=time(NULL);
    cout<<off-t<<endl;
}

#include <iostream>
using namespace std;
#include <time.h>
 
class b
{
public:
time_t timeAppStart;
time_t timeAppStop;
time_t timeOfAction;
void action(){
time_t timeAppWork=timeAppStart;
while (timeAppWork<timeAppStop){
time(&timeAppWork);
system("cls");
cout<<"Begins at "<<timeAppStart<<" \n\nthe time remain is "<<timeAppStop-timeAppWork<<endl;
}
}
 
b(time_t timeOfAction_)
:timeOfAction(timeOfAction_)
{
timeAppStop = time(&timeAppStart) + timeOfAction;
action();
}
~b()
{
time(&timeAppStop);
cout<<endl<<"Stoped at "<<timeAppStop<<endl;
}
};
void lauchit_now(time_t  timetowork){
b act(timetowork);
}
int main()
{
 lauchit_now(5);
system("pause");
cout<<endl<<endl;
  return 0;
}

#include <iostream>
#include <ctime>
#include <vector>
 
 
class B {
   time_t timeAppStart ;
   time_t timeAppStop ;
public :
   B ( ) {
      time( & timeAppStart ) ;
   }
   ~B ( ) {
      time( & timeAppStop ) ;
      std::cout << "Time : " << timeAppStop - timeAppStart << std::endl ;
   }
} ;
 
 
B g_Obj ;
 
 
int main ( ) {
   std::vector < int > vec ;
   std::cout << "Input numbers -> " ;
   while ( true ) {
      int x ;
      std::cin >> x ;
      if ( x == 0 )
         break ;
      vec.push_back ( x ) ;
   }
}

 
int main ( ) {
   std::vector < int > vec ;//что это?
   std::cout << "Input numbers -> " ;
   while ( true ) {
      int x ;
      std::cin >> x ;
      if ( x == 0 )
         break ;
      vec.push_back ( x ) ;
   }

#include <iostream>
#include <ctime>
#include <cstdlib>
 
 
class B {
   time_t timeAppStart ;
public :
   B ( ) {
      timeAppStart = clock ( ) ;
   }
   ~B ( ) {
      std::cout << "Time : " << static_cast < double > ( clock ( ) - timeAppStart ) / CLOCKS_PER_SEC << " sec." << std::endl ;
   }
} ;
 
 
B g_Obj ;
 
 
int main ( ) {
   system ( "pause" ) ;
}