Solution: Big (O) of Nested Loop with Subtraction

int main(){
  int n = 10;  
  int sum = 0;  
  float pie = 3.14;    
  for (int i=n; i>=1; i-=3){   // O(n/3)
    cout << pie << endl;    // O(n/3)
    for (int j=n; j>=0; j--){     // O((n/3)*(n+1))
      sum += 1;   // O((n/3)*(n+1))
    }
  }
  cout << sum << endl;    
}