Sum of divisors of an integer (~sqrt(N))
int main() { long n; cin >> n; long result = 0; for (long i=2; i<=sqrt(n); i++) { if (n%i==0) { if (i==(n/i)) result += i; else result += (i + n/i); } } cout << result << endl; }
int main() { long n; cin >> n; long result = 0; for (long i=2; i<=sqrt(n); i++) { if (n%i==0) { if (i==(n/i)) result += i; else result += (i + n/i); } } cout << result << endl; }