Program C++ menu case switch

mendekati UAS semester 2 di kasih tugas bikin program menu pake instruksi case switch, simple aja cuma gabungin program2 yang uda di buat di jadiin satu hhe...

/*program menu case switch hidayat chaniago ecD4 091354013*/

#include<iostream.h>

#include<stdio.h>

#include<conio.h>

#include<stdlib.h>

main(void)

{

char karakter,t;

int liter,solar,premium,super,a,b,c,simpanan,tebakan,i,ch,n,x;

float y,X1,X2,D;

z:

clrscr();

gotoxy(34,5);cout<<"pilih menu";

gotoxy(28,7);cout<<"1. program deret prima";

gotoxy(28,8);cout<<"2. program persamaan kuadrat";

gotoxy(28,9);cout<<"3. program a+(b*c)";

gotoxy(28,10);cout<<"4. program bensin while do";

gotoxy(28,11);cout<<"5. program tebak tebakan";

unsigned short int number;

gotoxy(28,13);cout<<"enter number 1 sampai 5: ";

cin>>number;

clrscr();

switch(number)

{

case 0:   cout<<"too small pilihan hanya 1 s/d 5\n";

                 break;

case 5:   while(1)

                   {  cout<<"saya menyimpan satu nilai antara 0 s/d 99.\n";

                      cout<<"silahkan anda tebak nilai tersebut.\n";

                      cout<<"-----------------------------------\n";

                      simpanan=rand()%100;

                      for(i=1;i<7;i++)

                      {  printf("tebakan ke-%d: ",i);

                         scanf("%d",&tebakan);

                         if(tebakan<simpanan)

                         {  printf("tebakan terlalu kecil!\n"); continue;}

                         if(tebakan==simpanan)

                         {  printf("anda pinter!\n"); break;}

                         printf("tebakan terlalu besar!\n");

                      }

                       if(i==7)

                        {  printf("anda kurang beruntung..\n");

                           printf("nilai simpanan adalah %d\n",simpanan);}

                           printf("anda ingin mengulang permainan(Y/N)?");

                           ch=getche();

                           if(!(ch=='Y'||ch=='y'))

                           break;

                         printf("\n\n");

                }

              break;

case 4:   cout<<"liter   solar   premium   super\n";

               cout<<"-------------------------------\n";

               liter=1;

               while(liter<=15)

               {  solar=liter*250;

                    premium=liter*385;

                    super=liter*450;

                    printf("%5d   %5d   %5d    %5d\n",liter,solar,premium,super);liter++;}

                  cout<<"------------------------------\n";

                 break;

case 3:   printf("masukan nilai a\n");

               scanf("%d",&a);

               printf("masukan nilai b\n");

                 scanf("%d",&b);

                 printf("masukan nilai c\n");

               scanf("%d",&c);

                  y=a+b*c;

                printf("hasil a(b*c) adalah :%3.2f", y);

                 break;

case 2:   gotoxy(16,10);printf("Program Menghitung Akar Persamaan Kuadrat");

                 gotoxy(18,12);printf("silahkan masukan nilai a,b,dan c, :\n");

                 gotoxy(30,14);printf("nilai a:");scanf("%d",&a);

               gotoxy(30,15);printf("nilai b:");scanf("%d",&b);

                 gotoxy(30,16);printf("nilai c:");scanf("%d",&c);

                  {

                   D=b*b-4*a*c;

                    if(D<0)

                    {  gotoxy(27,18);printf("Hasil Imajiner \n");}

                    else

                    {

                      X1=((-b+D)/2*a);

                      X2=((-b-D)/2*a);

                 gotoxy(23,17);printf("Hasil Persamaan Kuadrat: \n");

                 gotoxy(30,18);printf("X1=%3.2f\n", X1);

                 gotoxy(30,19);printf("X2=%3.2f\n", X2);

                }}

                 break;

case 1:   p:

                 clrscr();

                 do

                 {printf("banyak bilangan prima = ");

                scanf("%d",&n);}

                 while(n<=0);

                  x=0;

                 for(i=1;i<=30000;i++)

                {

                   if(i==1) {}

                   else

                   {

                     if(i==2 || i==3 || i==5 || i==7) {printf("%d  ",i); x=x+1;} else {}

                     if(i%2==0 || i%3==0 || i%5==0 || i%7==0) {}

                  else {printf("%d  ",i); x=x+1; }

                   }

                    if(x==n) {i=30000;} else{}

                   }

                    printf("\n\npress t to try again");

                    t=getch();

                    if(t=='t') {goto p;} else {}

                    break;

default:  cout<<"too large pilihan hanya 1 s/d 5\n";

break;

}

  printf("\n\ntekan x untuk kembali ke menu");

  karakter=getch();

  if(karakter=='x') {goto z;} else {}

}