fork(2) download
copy 
  1. #include <map>
  2. #include <cassert>
  3. #include <iostream>
  4.  
  5. template< typename T, typename U >
  6. auto infimum(std::map<T,U> const& ctr, T query)
  7. {
  8. 	auto it = ctr.upper_bound(query);
  9.     return ctr.empty() || it == ctr.begin() ? ctr.cend() : --it;
  10. }
  11.  
  12. template< typename T, typename U >
  13. bool is_in_interval(std::map<T,U> const& ctr, T query)
  14. {
  15.     auto inf = infimum(ctr, query);
  16.     return inf == ctr.end() ? false : query <= inf->second;
  17. }
  18.  
  19. int main()
  20. {
  21.     using std::cout;
  22.     using Map = std::map<int,int>;
  23.     Map intervals{{2,5}, {8,9}};
  24.  
  25.     auto red = infimum(intervals, 4);
  26.     assert(red->first == 2);
  27.     cout << "red->first " << red->first << "\n";
  28.  
  29.     auto green = infimum(intervals, 6);
  30.     assert(green->first == 2);
  31.     cout << "green->first " << green->first << "\n";
  32.  
  33.     auto pink = infimum(intervals, 8);
  34.     assert(pink->first == 8);
  35.     cout << "pink->first " << pink->first << "\n";
  36.  
  37.     auto yellow = infimum(intervals, 1);
  38.     assert(yellow == intervals.cend());
  39.  
  40.     auto larger_than_all = infimum(intervals, 15);
  41.     assert(larger_than_all->first == 8);
  42.  
  43.     bool red_is = is_in_interval(intervals, 4);
  44.     cout << "red is in " << red_is << "\n";
  45.  
  46.     bool green_is = is_in_interval(intervals, 6);
  47.     cout << "green is in " << green_is << "\n";
  48.  
  49.     bool pink_is = is_in_interval(intervals, 8);
  50.     cout << "pink is in " << pink_is << "\n";
  51.  
  52.     bool yellow_is = is_in_interval(intervals, 1);
  53.     cout << "yellow is in " << yellow_is << "\n";
  54. }
Success #stdin #stdout 0s 15240KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
red->first 2
green->first 2
pink->first 8
red is in 1
green is in 0
pink is in 1
yellow is in 0
https://ideone.com/jM8pt3
language:
C++14 (gcc 8.3)
created:
4 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!