C++ PROGRAM TO CONVERT TIME FROM 24-HR TO 12-HR FORMAT USING FRIEND CLASS AND PARAMETERISED CONSTRUCTOR.

Create a class time that has separate int member data for hours, minutes and seconds in which time is represented in 24-hr format. One constructor should initialize this data to zero and another constructor initialize it to fixed values. Another class is created to represent time in 12-hr format. A member function must be defined to convert 24-hr format to 12-hr format. A main() program should create objects of class time, read time in 24-hr format and convert it in to 12-hr format. 

#include<iostream.h>

#include<string.h>

#include<conio.h>

class time24

{

  int hours,minutes,seconds;

  public:

  time24()

  {

    hours=minutes=seconds=0;

  }

  time24(int h,int m,int s)

  {

    hours=h;

    minutes=m;

    seconds=s;

  }

  void display()

  {

    if(hours<10)

    cout<<'0';

    cout<<hours<<":";

    if(minutes<10)

      cout<<'0';

    cout<<minutes<<":";

    if(seconds<10)

      cout<<'0';

    cout<<seconds;

  }

  friend class time12;

};

class time12

{

  int pm;

  int hour,minute;

  char *am_pm;

  public:

  time12(time24);

  void display()

  {

    cout<<hour<<":";

    if(minute<10)

      cout<<'0';

    cout<<minute<<" ";

    cout<<am_pm;

  }

};

time12::time12(time24 t24)

{

  int hrs24=t24.hours;

  int pm=t24.hours<12 ? 0:1;

  int min=t24.seconds<30 ? t24.minutes:t24.minutes+1;

  if(min==60)

  {

    min=0;

    ++hrs24;

    if(hrs24==12 || hrs24==24)

    pm=(pm==1)? 0:1;

  }

  int hrs12=(hrs24<13) ? hrs24 : hrs24-12;

  if(hrs12==0)

  {

    hrs12=12;

    pm=0;

  }

    if(pm==1)

    {

      am_pm=" pm";

    }

    else

    {

      am_pm=" am";

    }

    hour=hrs12;

    minute=min;

}

int main()

{

  clrscr();

  int h1,m1,s1,x=1;

  while(x==1)

  {

    cout<<"enter 24-hour time:\n";

    cout<<"Hours(0-23):";

    cin>>h1;

    if(h1>23)

    return(1);

    cout<<"Minutes:";

    cin>>m1;

    cout<<"Seconds:";

    cin>>s1;

    time24 t24(h1,m1,s1);

    cout<<"you entered:";

    t24.display();

    cout<<endl;

    time12 t12=t24;

    cout<<"\n12-hour time:\n";

    t12.display();

    cout<<endl;

    x=0;

  }

  getch();

  return 0;

}

OUTPUT