PEMOGRAAMAN C++

#include<stdio.h>
#include<conio.h>
#include<iostream.h>
 main()
  {
   exit:
char yes;
clrscr();
cout<<"\n**************************************************"<<endl;
cout<<"* &&&&   &&&  &&    && &&&   &&&&  &&&  &&&&&&&&&*"<<endl;
cout<<"* &   & &   & &&    && &&&&  &&&& &   &    &&    *"<<endl;
cout<<"* &&&&& &   & &&&&&&&& &&  &&  && &   &    &&    *"<<endl;
cout<<"* &&&   & & & &&    && &&      && & & &    &&    *"<<endl;
cout<<"* && && &&  &&&&&   &&&&&      &&&&&  &&  &&&&   *"<<endl;
cout<<"*                                                *"<<endl;
cout<<"**************************************************"<<endl<<endl<<endl<<endl;
cout<<"                                     ***"<<endl;
cout<<"                       *PROGRAM MENGHITUNG NILAI AKHIR*"<<endl;

yesno:
    puts("                                      MASUK (y/n)");
    scanf("%c",&yes);
    if (yes == 'y' || yes == 'Y') {
          goto dor;  }

    else
      if (yes == 'n' || yes == 'N')
      {printf("oke, anda telah memilih untuk mengakhiri program ini\n");
      goto exit;}
      else{
          puts("pilih y atau n saja !!");
          goto yesno;}
dor:

  clrscr();
  char nm_mhs [40], gra [5];
  int niak, niat, niau, niamk, niamu,niamt, nia;
  clrscr();
  cout<<"     Selamat Datang di Program RAHMAT HIDAYAT    "<<endl;
  cout<<"\n============================================"<<endl;


  cout<<"     PROGRAM PENGHITUNGAN NILAI MAHASISWA"<<endl;
  cout<<"============================================"<<endl<<endl;
  cout<<"Nama Mahasisiswa      : ";cin>>nm_mhs;
  cout<<"Nilai keaktifan       : ";cin>>niak;
  cout<<"Nilai Tugas           : ";cin>>niat;
  cout<<"Nilai Ujian           : ";cin>>niau;

  niamk=niak*0.2;
  niamt=niat*0.3;
  niamu=niau*0.5;
  nia=niamk+niamt+niamu;

  if (nia >= 80)
  {strcpy(gra, "A");}
  else if (nia >= 70 && nia < 80)
  {strcpy(gra, "B");}
  else if (nia >= 56 && nia <70)
  {strcpy(gra, "C");}
  else if (nia >= 46 && nia < 56)
  {strcpy(gra, "D");}
  else
  {strcpy(gra, "E");}

  clrscr();
  cout<<"Siswa yang bernama "<<nm_mhs<<endl;
  cout<<"Dengan Nilai Presentasi Yang Dihasilkan."<<endl;
  cout<<"============================================="<<endl<<endl;
  cout<<"**********************************"<<endl;
  cout<<"* ============================== *"<<endl;
  cout<<"*| 1. Nilai Keaktifan x 20% : "<<niamk<<"|*"<<endl;
  cout<<"*| 2. Nilai Tugas     x 30% : "<<niamt<<"|*"<<endl;
  cout<<"*| 3. Nilai Ujian     x 50% : "<<niamu<<"|*"<<endl;
  cout<<"* ============================== *"<<endl;
  cout<<"**********************************"<<endl<<endl;
  cout<<"============================================="<<endl<<endl;
  cout<<"sehingga, Siswa yang bernama "<<nm_mhs;
  cout<<" memperoleh nilai akhir sebesar "<<nia;
  cout<<" \ndengan grade "<<gra;
  getch();
}