Advance Time Program in C++

Create a Class time that has separate int member data for hours,minutes and seconds.One constructor should initialize this data to 0 and another should initial;ize it to fixed values. Another member function should display it in 11:59:59 format. The final member function should add two time objects passed as arguments.

#include<iostream.h>

#include<conio.h>

class time

{private:int h;

             int m;

             int s;

 public:time()

            {h=0;m=0;s=0;}

            time(int a,int b,int c)

            {h=a;m=b;s=c;}

            void getdata();

            void showdata()

            {cout<<"\n the time -> "<<h<<":"<<m<<":"<<s<<".";

             cout<<"\n";

             getch();

            }

            void sum(time a,time b)

            {int t=0;

             h=a.h+b.h;

             m=a.m+b.m;

             s=a.s+b.s;

             if(s>60)

             {t=s/60;

              s=s-(60*t);

              m=m+t;

             }

             t=0;

             if(m>60)

             {t=m/60;

              m=m-(60*t);

              h=h+t;

             }

            }

}t1,t2,t3;

void time :: getdata()

{int c=0,t=0;

 clrscr();

 while(c==0)

 {cout<<"\n enter the parameters of time \n";

  cout<<"\n enter seconds: ";

  cin>>s;

  if(s<0)

  {cout<<"\n please enter the positive value \n";

  }

  else

  {if(s>60)

   {t=s/60;

    s=s-(t*60);

   }

   c=1;

  }

 }

 c=1;

 while(c==1)

 {cout<<"\n enter minutes: ";

  cin>>m;

  if(m<0)

  {cout<<"\n you have entered wrong value enter again";

  }

  else

  {m=m+t;

   if(m>60)

   {t=m/60;

     m=m-(t*60);

   }

   else

   {t=0;}

   c=0;

  }

 }

 c=0;

 while(c==0)

 {cout<<"\n enter hour: ";

  cin>>h;

  if(h<0)

  {cout<<"\n sorry you have entered wrong value enter again";

  }

  else

  {h=h+t;

   c=1;

  }

 }

}

void main()

{int n,i;

 clrscr();

 t1.getdata();

 t1.showdata();

 t2.getdata();

 t2.showdata();

 cout<<" sum of";

 t3.sum(t1,t2);

 t3.showdata();

 getch();

}