fork download 
  1. #include <iostream>
  2.  
  3. int divisorsSum( int x )
  4. {
  5.     int result = 1;
  6.     int upperLimit = x / 2 + 1;
  7.  
  8.     for ( int d = 2; d < upperLimit; ++d )
  9.     {
  10.         if ( x % d == 0 )
  11.         {
  12.             result += d;
  13.             result += (x / d);
  14.             upperLimit = (x / d);
  15.         }
  16.     }
  17.  
  18.     return result;
  19. }
  20.  
  21. void findNFriends( int n )
  22. {
  23.     int findedCount = 0;
  24.     for ( int f = 220; ; ++f )
  25.     {
  26.         int s = divisorsSum( f );
  27.         if ( (f < s) && (f % 2 == s % 2) && (f == divisorsSum( s )) )
  28.         {
  29.             ++findedCount;
  30.             std::cout << "(" << f << ", " << s << ")" << std::endl;
  31.  
  32.             if ( findedCount >= n ) break;
  33.         }
  34.     }
  35. }
  36.  
  37. int main() {
  38.     findNFriends(14);
  39.     return 0;
  40. }
Success #stdin #stdout 11.85s 2724KB
comments (?)
stdin 
Standard input is empty
stdout 
(220, 284)
(1184, 1210)
(2620, 2924)
(5020, 5564)
(6232, 6368)
(10744, 10856)
(12285, 14595)
(17296, 18416)
(63020, 76084)
(66928, 66992)
(67095, 71145)
(69615, 87633)
(79750, 88730)
(100485, 124155)
https://ideone.com/6XwxCw
language:
C++ (gcc 8.3)
created:
13 years 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!