#include <iostream>
int main(){
int n;
unsigned long long int p=1;
for(n=1;n<=21;n++){
if(n%2==1)
p=p*n;
}
cout<<"p="<<p;
return 0;
}
Sau, a 2-a metoda, mai eficienta si mai rapida:
int main(){
int n;
unsigned long long int p=1;
for(n=1;n<=21;n=n+2){
p=p*n;
}
cout<<"p="<<p;
return 0;
}