Как переделать из С++ в С#

#include <iostream.h>
#include <cstdlib>
 
struct LIST {
 
 
int info; 
LIST *next; 
LIST *prev; 
};
 
LIST *head;
int n1, n2;
 
void Initial()
{
 
 
head = new LIST; 
head->next=head; 
head->prev=head; 
}
 
int Empty()
{
 
 
if (head->next==head && head->prev==head) 
return 1; 
else 
return 0; 
}
 
LIST *SearchOnward(int num)
{
 
 
LIST *tmp=head->next; 
while(tmp!=head && tmp->info!=num) 
{ 
tmp=tmp->next; 
n1+=1; 
} 
if (tmp!=head) 
return tmp; 
else 
return NULL; 
}
 
LIST *SearchBack(int num)
{
 
 
LIST *tmp=head->prev; 
while(tmp!=head && tmp->info!=num) 
{ 
tmp=tmp->prev; 
n2+=1; 
} 
if (tmp!=head) 
return tmp; 
else 
return NULL; 
}
 
int Del(int num)
{
 
 
LIST *current=SearchOnward(num); 
if (current!=NULL) 
{ 
current->prev->next=current->next; 
current->next->prev=current->prev; 
delete current; 
return 1; 
} 
return 0; 
} 
 
int AddAfter(int num, int point)
{
 
 
if (Empty()==1) 
{ 
LIST *tmp= new LIST; 
tmp->next=head; 
tmp->prev=head; 
tmp->info=num; 
head->next=tmp; 
head->prev=tmp; 
return 1; 
} 
LIST *current=SearchOnward(point); 
if (current!=NULL) 
{ 
LIST *tmp= new LIST; 
tmp->next=current->next; 
tmp->prev=current; 
tmp->info=num; 
current->next->prev=tmp; 
current->next=tmp; 
return 1; 
} 
return 0; 
}
 
int AddBefore(int num, int point)
{
 
 
LIST *current=SearchBack(point); 
if(current!=NULL) 
{ 
LIST *tmp= new LIST; 
tmp->info=num; 
tmp->next=current; 
tmp->prev=current->prev; 
current->prev->next=tmp; 
current->prev=tmp; 
return 1; 
} 
return 0; 
}
 
void ShowOnward()
{
 
 
LIST *tmp=head->next; 
cout << endl << "V priamom napravlenii:" << endl; 
while(tmp!=head) 
{ 
cout << tmp->info << " "; 
tmp=tmp->next; 
} 
cout << endl; 
}
 
void ShowBack()
{
 
 
LIST *tmp=head->prev; 
cout << endl << "V obratnom napravlenii:" << endl; 
while(tmp!=head) 
{ 
cout << tmp->info << " "; 
tmp=tmp->prev; 
} 
cout << endl; 
}
 
int main()
{
 
 
Initial(); 
int num, tmp; 
char otv, otv2; 
do 
{ 
 
cout << "1. Add" << endl 
<< "2. Delet" << endl 
<< "3. VVOD"<< endl 
<< "4. Search" << endl 
<< "0. Exit" << endl 
<< " = "; 
cin >> otv; 
switch(otv) 
{ 
case '1': 
 
cout << endl << "vvedite element = "; 
cin >> num; 
if (Empty()==1) 
{ 
AddAfter(num,0); 
cout << endl << "Element dobavlen" << endl; 
} 
else 
{ 
 
cout << endl << "1. Dobavit pered" 
<< endl << "2. Dobavit pole" 
<< endl << " = "; 
cin >> otv2; 
switch(otv2) 
{ 
case '1': 
 
cout << endl << "Pered kakim elementom dobavit = "; 
cin >> tmp; 
if (AddBefore(num,tmp)==1) 
cout << endl << "Element dobavlen" << endl; 
else 
cout << endl << "Takogo elementa net" << endl; 
break; 
case '2':
 
 
cout << endl << "Posle kakogo elementa dobavit = "; 
cin >> tmp; 
if (AddAfter(num,tmp)==1) 
cout << endl << "Element dobavlen" << endl; 
else 
cout << endl << "Net takogo elementa" << endl; 
break; 
default:
 
 
cout << endl << "Error" << endl; 
break; 
}
 
}
break;
 
case '2':
 
 
if(Empty()==1) 
cout << endl << "List Empty" << endl; 
else 
{ 
cout << endl << "ydaliaemi element = "; 
cin >> num; 
if(Del(num)==1) 
cout << endl << "Element ydalen" << endl; 
else 
cout << endl << "Net takogo elementa" << endl; 
} 
break; 
case '3':
 
 
if(Empty()==1) 
cout << endl << "List EMPTY" << endl; 
else 
{ 
cout << endl << "1. Obhod v priamom napravlenii" << endl
<< "2. Obhod v obratnom napravlenii" << endl
<< " = ";
cin >> otv2;
switch(otv2)
{
case '1':
 
 
ShowOnward(); 
break; 
case '2':
 
 
ShowBack(); 
break; 
default:
 
 
cout << endl << "Error" << endl; 
break; 
} 
 
}
break;
 
case '4':
 
 
if(Empty()==1) 
cout << endl << "list EMPTY" << endl; 
else 
{ 
 
cout << endl << "Element dlia poiska = "; 
cin >> num; 
n1=0; 
n2=0; 
if(SearchOnward(num)!=NULL && SearchBack(num)!=NULL) 
{ 
cout << endl << "Element naiden\n" << endl; 
cout << endl << "Shag v priamom napravlenii = \n" << n1 << endl; 
cout << endl << "shag v obratnom napravlenii = \n" << n2 << endl; 
} 
else 
cout << endl << "Takogo elementa net\n" << endl; 
}
break;
 
case '0':
 
 
break; 
default:
 
 
cout << endl << "Vixod" << endl; 
break; 
}
 
}while(otv!='0');
cin.get();
 
}