sorting full

#include <iostream.h>
#include <conio.h>

struct {
char nama[20];
char nim[20];
int tgl,bln,thn;
int jk;
float ipk;}data[20];


void main(){
  int j,i,tl,n,temp,pilih,thn,umur[100000],bill[20],uur;
  int umurr[20];
  char lagi;
  float bil[20];
    cout<<"Tahun Sekarang\t\t = ";cin>>thn;
    cout<<"\nJumlah Mahasiswa : ";cin>>n;
    clrscr();
    for(i=1;i<=n;i++){
    cout<<"Mahasiswa ke "<<i;
    cout<<"\nNama\t\t = ";cin>>data[i].nama;
    cout<<"NIM\t\t = ";cin>>data[i].nim;
    cout<<"Tahun Lahir\t\t = ";cin>>tl;
    uur=thn-tl;
    umur[i]=uur;
    umurr[i]=umur[i];
    cout<<"\tJenis Kelamin";
    cout<<"\n1. Laki-laki";
    cout<<"\n2. Perempuan";
    cout<<"\nPilih : ";cin>>data[i].jk; bill[i]=data[i].jk;
    cout<<"\nIPK \t\t = ";cin>>data[i].ipk; bil[i]=data[i].ipk;
    clrscr();}

atas:
     cout<<"Sorting Berdasarkan : ";
     cout<<"\n1. IPK";
     cout<<"\n2. Umur";
     cout<<"\n3. Jenis Kelamin";
     cout<<"\nPilihan = ";cin>>pilih;

   switch(pilih){
   case 1 :
   for(i=1;i<=n;i++){
for(j=1;j<=n;j++){
if(bil[i]<bil[j]){  temp=bil[i];
                     bil[i]=bil[j];
                     bil[j]=temp;  }}}


 for(i=1;i<=n;i++){
 for(j=1;j<=n;j++){
  if(bil[i]==data[j].ipk ){
 cout<<"\nnama \t: "<<data[j].nama;
 cout<<"\nNIM \t: "<<data[j].nim;
 cout<<"\nUmur \t: "<<umurr[j];
 cout<<"\nJenis Kelamin \t: ";if(data[i].jk%2==0){cout<<"Perempuan";} else {cout<<"Laki-laki";}
 cout<<"\nipk \t: "<<data[j].ipk;
 cout<<endl; }}}
   break;
   case 2 :
    for(i=1;i<=n;i++){
for(j=1;j<=n;j++){
if(umurr[i]<umurr[j]){  temp=umurr[i];
                     umurr[i]=umurr[j];
                     umurr[j]=temp;  }}}

 for(i=1;i<=n;i++){
 for(j=1;j<=n;j++){
  if(umurr[i]==umur[j]){
 cout<<"\nnama \t: "<<data[j].nama;
 cout<<"\nNIM \t: "<<data[j].nim;
 cout<<"\nUmur \t: "<<umurr[j];
 cout<<"\nJenis Kelamin \t: ";if(data[i].jk%2==0){cout<<"Perempuan";}else{cout<<"Laki-laki";}
 cout<<"\nipk \t: "<<data[j].ipk;
 cout<<endl; }}}

   break;
   case 3 :
   for(i=1;i<=n;i++){
  if(data[i].jk%2==0){
 cout<<"\nnama \t: "<<data[i].nama;
 cout<<"\nNIM \t: "<<data[i].nim;
 cout<<"\nUmur \t: "<<umurr[i];
 cout<<"\nJenis Kelamin \t: Perempuan";
 cout<<"\nipk \t: "<<data[i].ipk;
 cout<<endl; } }

  for(i=1;i<=n;i++){
  if(data[i].jk%2==1){
 cout<<"\nnama \t: "<<data[i].nama;
 cout<<"\nNIM \t: "<<data[i].nim;
 cout<<"\nUmur \t: "<<umurr[i];
 cout<<"\nJenis Kelamin \t: Laki-laki";
 cout<<"\nipk \t: "<<data[i].ipk;
 cout<<endl; } }

   break;
   }