Program penjumlahan array 2 dimensi bilangan prima dan Structure C++

#include <iostream>
#include <stdlib.h>
#include <conio.h>
using namespace std;
int pilih;
void kembalimenu1();
void kembalimenu2();
void kembalimenu3();
void kembalimenu4();
void kembalimenu5();
void exit();
void satu()
{
    int j,k,l,m;
    system("cls");
    cout<<"Matrix A"<<endl;
    cout<<"Input Row: ";
    cin>>j;
    cout<<"Input Coloumn: ";
    cin>>k;
    int matrik_a[j][k];
    for(int bar=0;bar<j;bar++){
        for(int kol=0;kol<k;kol++){
            cout<<"A["<<bar+1<<"]["<<kol+1<<"] = ";
            cin>>matrik_a[bar][kol];
        }
    }
    cout<<endl;
    for(int bar=0;bar<j;bar++){
        for(int kol=0;kol<k;kol++){
            cout<<matrik_a[bar][kol]<<"\t";
        }
        cout<<endl<<endl;
    }

    cout<<"Matrix B"<<endl;
    cout<<"Input Row: ";
    cin>>l;
    cout<<"Input Coloumn : ";
    cin>>m;
    int matrik_b[l][m];
    for(int bar=0;bar<l;bar++){
        for(int kol=0;kol<m;kol++){
            cout<<"B["<<bar+1<<"]["<<kol+1<<"] = ";
            cin>>matrik_b[bar][kol];
        }
    }
    cout<<endl;
    for(int bar=0;bar<l;bar++){
        for(int kol=0;kol<m;kol++){
            cout<<matrik_b[bar][kol]<<"\t";
        }
        cout<<endl<<endl;
    }

    if(j == l,k == l)
    {
      cout<<"Amount Between Matrix A & Matrix B"<<endl;
      int matrik_c[l][m];
      for(int bar=0;bar<l;bar++)
      {
        for(int kol=0;kol<m;kol++)
        {
           matrik_c[bar][kol]=matrik_a[bar][kol]+matrik_b[bar][kol];
       }
   }
   cout<<endl;
   for(int bar=0;bar<l;bar++)
   {
    for(int kol=0;kol<m;kol++)
    {
       cout<<matrik_c[bar][kol]<<"\t";
   }
   cout<<endl<<endl;
}

}
else
{
  cout<<" Baris dan Kolom Tidak Bisa Dioperasikan";
}
kembalimenu1();
}
void dua()
{
   int a,b,x,y,z;
   system("cls");
   cout<<"Masukkan banyak data : ";
   cin>>x;

   for(a=x;a>=1;a--)
   {
    y=0;
    cout<<endl;
    for(b=1;b<=a;b++)
    {
        cout<<(b*2)-1;
        y=y+(b*2)-1;
        if(b<a)
        {
            cout<<" + ";
        }
        else{
            cout<<" = "<<y;
        }
    }
    cout<<endl;

}
for(a=2;a<=x;a++)
{
    z=0;
    cout<<endl;
    for(b=1;b<=a;b++)
    {
        cout<<(b*2)-1;
        z=z+(b*2)-1;
        if(a>b)
        {
            cout<<" + ";
        }
        else{
            cout<<" = "<<z;
        }
    }
    cout<<endl;

}
kembalimenu2();

}


void tiga()
{
    int batas,x,y,cek,z;
    system("cls");
    cout<<"Masukkan batas dari deret bilangan prima ";
    cin>>batas;
    cout<<"\nDeret bilangan prima sampai angka "<<batas<<" adalah :"<<endl<<endl;
    for (x=2;x<=batas;x++)
    {
        cek=0;
        for (y=2;y<x;y++)
        {
            if(x%y==0)
            {
                cek=1;
            }
        }
        if(cek==0)
        {
            cout<<x<<" ";
        }
        if(x<batas)
        {
            cout<<" + ";
        }
        else
        {
            cout<<" = "<<x+6<<" ";
        }

    }
    kembalimenu3();
}
void empat()
{
    system("cls");
    struct stud
    {
        char name_stud[3][10];
        int id_stud[5];
        char prodi[5][10];
    };
    stud stud1;
    struct scr
    {
        int mid[5],final[9],assign[10],nilai[10];
        char grade[40];
    };
    scr scr1;
    struct lect
    {
        int id_lect[10];
        char name_lect[20][30];
        char subject[9][10];
    };
    lect lect1;
    {
        int limit;
        cout<<"enter the limit =";
        cin>>limit ;
        for(int x=1;x<=limit;x++)
        {
            cout<<"\tdata"<<x<<endl;
            cout<<"\nid_students=";cin>>stud1.id_stud[x];
            cout<<"\nname_student=";cin>>stud1.name_stud[x];
            cout<<"\nsubject=";cin>>lect1.subject[x];
            cout<<"\ngrade=";cin>>scr1.grade[x];
            cout<<"\nid_lect=";cin>>lect1.id_lect[x];
            cout<<"\nname_lect=";cin>>lect1.name_lect[x];
        }
        cout<<"No"<<"\t"<<"id_stud"<<"\t"<<"name_stud"<<"\t"<<"subject"<<"\t"<<"grade"<<"\t"<<"id_lect"<<"\t"<<"name_lect";
        cout<<endl;
        for(int x=1;x<=limit;x++)
        {
            cout<<stud1.id_stud[x]<<"\t"<<stud1.name_stud[x]<<"\t"<<lect1.subject[x]<<"\t"<<scr1.grade[x]<<"\t"<<lect1.id_lect[x]<<"\t"<<lect1.name_lect[x];
            cout<<endl;
        }
    }
    kembalimenu4();
}
void lima()
{
    system("cls");
    cout<<"Keluar";
    kembalimenu5();
}

main()
{
    system("cls");
    cout<<"***********Menu Program********"<<endl;
    cout<<"1.Penjumlahan Array 2 Dimensi"<<endl;
    cout<<"2.Deret"<<endl;
    cout<<"3.Bilangan Prima"<<endl;
    cout<<"4.Structure"<<endl;
    cout<<"5.Exit"<<endl;
    cout<<"Masukkan pilihan Anda [1],[2],[3],[4],[5]="<<endl;
    cin>>pilih;
    if(pilih==1)
    {

       satu();
   }
   else if(pilih==2)
   {
     dua();
 }
 else if(pilih==3)
 {
    tiga();
}
else if(pilih==4)
{
    empat();
}
else{
    cout<<"Terima Kasih Program Anda Selesai";
}
}
void kembalimenu1()
{

    char yn;
    cout<<endl;
    cout<<"Back to Menu[Y/N/T]";
    cin>>yn;
    if(yn=='Y' || yn=='y'){
        main();}
        else if(yn=='N' ||yn=='n')
        {
        }
        else if(yn=='T' || yn=='t' )
        {
            satu();
        }
    }
    void kembalimenu2()
    {

        char yn;
        cout<<endl;
        cout<<"Back to Menu[Y/N/T]";
        cin>>yn;
        if(yn=='Y' || yn=='y'){
            main();}
            else if(yn=='N' ||yn=='n')
            {
            }
            else if(yn=='T' || yn=='t' )
            {
                dua();
            }
        }

        void kembalimenu3()
        {

            char yn;
            cout<<endl;
            cout<<"Back to Menu[Y/N/T]";
            cin>>yn;
            if(yn=='Y' || yn=='y'){
                main();}
                else if(yn=='N' ||yn=='n')
                {
                }
                else if(yn=='T' || yn=='t' )
                {
                    tiga();
                }
            }
            void kembalimenu4()
            {

                char yn;
                cout<<endl;
                cout<<"Back to Menu[Y/N/T]";
                cin>>yn;
                if(yn=='Y' || yn=='y'){
                    main();}
                    else if(yn=='N' ||yn=='n')
                    {
                    }
                    else if(yn=='T' || yn=='t' )
                    {
                        empat();
                    }
                }
                void kembalimenu5()
                {

                    char yn;
                    cout<<endl;
                    cout<<"Back to Menu[Y/N/T]";
                    cin>>yn;
                    if(yn=='Y' || yn=='y'){
                        main();}
                        else if(yn=='N' ||yn=='n')
                        {
                        }
                        else if(yn=='T' || yn=='t' )
                        {
                            lima();
                        }
                    }