fork download
copy 
  1. #include <bits/stdc++.h>
  2.  
  3. using namespace std;
  4.  
  5. typedef int T;
  6.  
  7. class tutorial_t: vector< T >
  8. {
  9.     T val; iterator it, iu;
  10.  
  11.     void example(   const function< iterator() >& bound_function,
  12.                     const function< bool( const T&, const T& ) >& bound_operator,
  13.                     const string& function_name,
  14.                     const string& operator_name ) const
  15.     {
  16.         iterator iv = bound_function(); cout << function_name << "( begin(), end(), " << val << " ): ";
  17.  
  18.         if ( iv != iu )
  19.             cout << "Found " << *iv << " at position " << ( iv - it ) << endl;
  20.         else
  21.             cout << "Not found! all items are " << operator_name << ' ' << val << endl;
  22.  
  23.         assert( iv == iu or not bound_operator( *iv, val ) );
  24.     }
  25.  
  26. public:
  27.  
  28.     tutorial_t()
  29.     {
  30.         size_t n; cin >> n >> val, resize( n ), it = begin(), iu = end();
  31.  
  32.         for( auto& a: *this )
  33.             cin >> a;
  34.  
  35.         sort( it, iu ), cout << "sorted_vector(" << n << "):";
  36.  
  37.         for( auto a: *this )
  38.             cout << ' ' << a;
  39.  
  40.         cout << endl, assert( is_sorted( it, iu ) );
  41.  
  42.         example( [&]() { return lower_bound( it, iu, val ); },       less< T >(), "lower_bound", "<"  ),
  43.         example( [&]() { return upper_bound( it, iu, val ); }, less_equal< T >(), "upper_bound", "<=" );
  44.     }
  45. };
  46.  
  47. int main()
  48. {
  49.     ios_base::sync_with_stdio( false ), cin.tie( nullptr ), cout.tie( nullptr );
  50.  
  51.     tutorial_t tutorial;
  52. }
  53.  
Success #stdin #stdout 0s 15240KB
comments (?)
stdin
copy 
8 20
10 20 30 30 20 10 10 20
stdout
copy 
sorted_vector(8): 10 10 10 20 20 20 30 30
lower_bound( begin(), end(), 20 ): Found 20 at position 3
upper_bound( begin(), end(), 20 ): Found 30 at position 6
https://ideone.com/Xc8gjs
A tutorial C++ class on using the standard library functions std::lower_bound and std::upper_bound
language:
C++14 (gcc 8.3)
created:
6 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!