Răspuns :
în C++ ?
# include <iostream>
using namespace std;
int n,S;
int main ()
{
cin>>n;
S=n*(n+1);
cout<<S;
return 0;
}
S=2(1+2+3+...+n)
S=2*n*(n+1):2
S=n*(n+1)
# include <iostream>
using namespace std;
int n,S;
int main ()
{
cin>>n;
S=n*(n+1);
cout<<S;
return 0;
}
S=2(1+2+3+...+n)
S=2*n*(n+1):2
S=n*(n+1)