algoritma Penghitung Akar-Akar Persamaan Kuadrat dan Konversi Bilangan Desimal ke Bilangan Biner bahasa c

#include<stdio.h>
#include<conio.h>
#include <math.h>

void main()
{
     int Q,m[20],n,i,j,tahun;

     double a,b,c,deskriminan,x1,x2,re,im;

     char S[12];
     i=0; n=0;
     do
     {
         printf("Tugas Akhir Semester Pemrograman Komputer\n\n");
         printf("Anggota Kelompok : \n\n");
         printf("Mismaya Marry Dany : 092143498\n");
         printf("Septi Widyaningsih : 092143528\n");
         printf("Siti Fajaroh       : 092143531\n");
         printf("Semester           : VC\n\n");
        printf("\n");
        printf("                         PROGRAM MATEMATIKA \n\n\n");
        printf("1. Program Penghitung Akar-Akar Persamaan Kuadrat\n");
        printf("2. Program Konversi Bilangan Desimal ke Bilangan Biner\n");
        printf("Silahkan pilih program yang akan dijalankan : ");
        scanf("%d",&Q);
        printf("\n\n------------------------------------------------------------------------------- \n\n");
        switch (Q)
           {
                 case 1:
                 printf("                         Program Penghitung Akar-Akar Persamaan Kuadrat \n\n\n");
                 printf(" \nMasukkan Nilai a:");
                 scanf ("%lf",&a);
                 printf("\nMasukkan Nilai b:");
                 scanf ("%lf",&b);
                 printf ("\nMasukkan Nilai c:");
                 scanf ("%lf",&c);
                     /* Hitung deskriminan*/
                 deskriminan=b*b-4*a*c;
                    /* Evaluasi deskriminan*/
                 if(deskriminan>0)
                 {
                     x1= (-b+ sqrt(deskriminan))/(2*a);
                     x2= (-b- sqrt(deskriminan))/(2*a);
                     printf(" \nAkar Real:\n");
                     printf("x1=%lf\n",x1);
                     printf("x2=%lf\n",x2);
                 }
                 else
                     if(deskriminan==0)
                        {
                            x1=-b/(2*a);
                            x2=x1;
                            printf("\nAkar Kembar:\n");
                            printf("x1=%lf\n",x1);
                            printf("x2=%lf\n",x2);
                        }


                     else /* deskriminan <0*/
                        {
                            re=-b/(2*a);
                            im=sqrt(fabs(deskriminan))/(2*a);
                            printf("\nAkar Kompleks\n");
                            printf("x1=%lf+%lfj\n",re,im);
                            printf("x2=%lf-%lfj\n",re,im);
                        }

                  break;
                  case 2:
                 printf ("                 Program Konversi Bilangan Desimal ke Bilangan Biner\n\n\n");
                 printf("Masukkan Bilangan Desimal : ");
                 scanf("%d",&n);
                 while(n != 0)
                   {
                       m[i]=n%2;
                       n=n/2;
                       i++;
                   }
                  printf("Bilangan binernya adalah\n");
                  if(i==0)
                     printf("0");
                  else
                     for(j=i-1;j>=0;j--)
                    {
                       printf("%d",m[j]);
                    }
                 printf("\n");
                 getche();
                 break;
                  default: printf("\n\nHarap pilih 1atau 2!\n\n");
         }
          printf("\n\n------------------------------------------------------------------------------\n\n");
          printf("Ulangi program ini?\n(y/n): \n\n");
          scanf("%s",S);
     }
     while ((strcmp(S,"y")==0)||(strcmp(S,"Y")==0));
     system ("cls");
}