fork download 
  1. #include<bits/stdc++.h>
  2. using namespace std;
  3. int main(){
  4.     long long n, a, sum=0;
  5.     cin >> n;
  6.     a = (n - (n % 9)) / 9 -1* (n % 9 == 0);
  7.         for (long long i=1; i <=a; i++)
  8.             sum +=i * 9;
  9.             cout << sum;
  10.         return 0;
  11. }
  12.  
  13.  
  14.  
Success #stdin #stdout 0s 5324KB
comments (?)
stdin 
20
stdout 
27
https://ideone.com/nX5jcZ
language:
C++14 (gcc 8.3)
created:
2 days ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!