Potongan - potongan Source Code DLLNC (Double Linked List Non Circular)

//Fungsi Inisialisasi DLLNC 
TNode *head, *tail; 
void init(){ 
head = NULL; 
tail = NULL; 
} 


//Function untuk mengetahui kosong tidaknya DLLNC 
int isEmpty (){ 
if(tail == NULL) return 1; 
else return 0; 
} 


//Tambah Depan 
void insertDepan ( int databaru ){ 
TNode * baru ; 
baru = new TNode ; 
baru ->data = databaru ; 
baru ->next = NULL; 
baru -> prev = NULL; 
if( isEmpty ()==1){ 
head= baru ; 
tail=head; 
head->next = NULL; 
head-> prev = NULL; 
tail-> prev = NULL; 
tail->next = NULL; 
} 
else { 
baru ->next = head; 
head-> prev = baru ; 
head = baru ; 
} 
cout <<"Data masuk \n"; 
} 


//Tambah node Belakang
void insertBelakang ( int databaru ){ 
TNode * baru ; 
baru = new TNode ; 
baru ->data = databaru ; 
baru ->next = NULL; 
baru -> prev = NULL; 
if( isEmpty ()==1){ 
head= baru ; 
tail=head; 
head->next = NULL; 
head-> prev = NULL; 
tail-> prev = NULL; 
tail->next = NULL; 
} 
else { 
tail->next = baru ; 
baru -> prev = tail; 
tail = baru ; 
tail->next = NULL; 
} 
cout <<"Data masuk \n"; 
} 




//Function untuk menampilkan isi linked list 
void tampil (){ 
TNode *bantu; 
bantu = head; 
if( isEmpty ()==0){ 
while(bantu!=tail->next){ 
cout <data<<" "; 
bantu=bantu->next; 
} 
cout << endl ; 
} else cout <<" Masih kosong \n"; 
}


//Function untuk menghapus data di data terdepan 
void hapusDepan (){ 
TNode * hapus ; 
int d; 
if ( isEmpty ()==0){ 
if(head->next != NULL){ 
hapus = head; 
d = hapus ->data; 
head = head->next; 
head-> prev = NULL; 
delete hapus ; 
} else { 
d = head->data; 
head = NULL; 
tail = NULL; 
} 
cout <<<" terhapus \n"; 
} else cout <<" Masih kosong \n"; 
} 


//Function untuk menghapus node terbelakang 
void hapusBelakang (){ 
TNode * hapus ; 
int d; 
if ( isEmpty ()==0){ 
if(head->next != NULL){ 
hapus = tail; 
d = tail->data; 
tail = tail-> prev ; 
tail->next = NULL; 
delete hapus ; 
} else { 
d = head->data; 
head = NULL; 
tail = NULL; 
} 
cout <<<" terhapus \n"; 
} else cout <<" Masih kosong \n"; }
}


//Function untuk menghapus semua elemen LinkedList 
void clear(){ 
TNode *bantu,* hapus ; 
bantu = head; 
while(bantu!=NULL){ 
hapus = bantu; 
bantu = bantu->next; 
delete hapus ; 
} 
head = NULL; 
tail = NULL; 
}