[fmmctg0001]

please somebody can help to debugging this

// recursive power , compute xn
int exp(int x, int n){
if(n==_______)
return _________;
return ____________*exp(_________);
}
void main(){
int a,b;
cin >>a>>b;
cout<<endl<<exp(a,b)<<endl;
}
// recursive print of a string
void print(char* s){
if(*s==____________)
return;
cout<<*s;
print(______________);
}
void main(){
char a[6]="hello";
print(a);
}
// recursive reverse print of a string
void rev_print(char* s){
if(*s==____________)
return;
____________________________;
___________________________;
}
void main(){
char a[100];
cin>>a;
rev_print(a);
}6
// recursive reverse print of an integer
void rev_print(int n){
if(n/10==0){
cout<<n%10;
return;
}
cout<<__________________________;
rev_print(___________________); 
}
void main(){
int a;
cin>>a;
rev_print(a);
}
// recursive print of an integer
void print(int n){
if(n/10==0){
cout<<n%10;
return;
}
print(_______________);
cout<<___________________;
}
void main(){
int a;
cin>>a;
print(a);
}