fork download 
  1. #include <iostream>
  2. #include <algorithm>
  3. #include <functional>
  4. #include <boost/iterator/indirect_iterator.hpp>
  5.  
  6. template<size_t R, size_t C>
  7. void sort_every_col(int (&a)[R][C])
  8. {
  9.     for(size_t c = 0; c < C; ++c)
  10.     {
  11.         int *tmp[R];
  12.         for(size_t r = 0; r < R; ++r)
  13.             tmp[r] = &a[r][c];
  14.         std::sort(boost::make_indirect_iterator(tmp),
  15.                   boost::make_indirect_iterator(tmp+R),
  16.                   std::greater<int>());
  17.     }
  18. }
  19.  
  20.  
  21. template<size_t R, size_t C>
  22. void print_array(int (&a)[R][C])
  23. {
  24.     for(size_t r = 0; r < R; ++r)
  25.     {
  26.         for(size_t c = 0; c < C; ++c)
  27.             std::cout << a[r][c] << ' ';
  28.         std::cout << '\n';
  29.     }
  30. }
  31.  
  32.  
  33. int main()
  34. {
  35.     int a2[3][3] = {{1, 2, 3},
  36.                     {4, 5, 6},
  37.                     {7, 8, 9}};
  38.  
  39.     sort_every_col(a2);
  40.     print_array(a2);
  41. }
  42.  
Success #stdin #stdout 0.02s 2724KB
comments (?)
stdin 
Standard input is empty
stdout 
7 8 9 
4 5 6 
1 2 3
https://ideone.com/1Wpjh9
language:
C++ (gcc 8.3)
created:
11 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!