1) #include<iostream.h>
using namespace std ;
int main (){int n,s=0 ,p=1;
cout<<"N: " ;
cin>>n;
while(n>0) {s=s+n;
p=p*n;
n--;}
cout<<"Suma : " <<s<endl ;
cout<<"Produs : " <<p;}
2)#include<iostream.h>
using namespace std ;
int main () { int n , s=0;
cout<<"N: ";
cin>>n;
while(n>0) { s=s+n%10;
n=n/10;}
cout<<"Suma : "<<s;}
3)#include<iostream.h>
using namespace std ;
int main (){int n , invers =0;
cout<<"N: ";
cin>>n;
while(n>0){ invers = invers*10+n%10;
n=n/10;}
cout<<"Inversul e : " <<invers ; }