Просмотр исходного текста страницы C++/Set Multiset/intersect

==Create the intersection of list1 and list2==


   
<source lang="cpp">  
#include <iostream>
#include <list>
#include <algorithm>
using namespace std;
template<class InIter>
void show_range(const char *msg, InIter start, InIter end);
int main()
{
  list<char> list1, list2, result(15);
  list<char>::iterator res_end;
  for(int i=0; i < 5; i++) 
     list1.push_back("A"+i);
  for(int i=3; i < 10; i++) 
     list2.push_back("A"+i);
     
  show_range("Contents of list1: ", list1.begin(), list1.end());
  show_range("Contents of list2: ", list2.begin(), list2.end());
  res_end = set_intersection(list1.begin(), list1.end(),list2.begin(), list2.end(),result.begin());
  show_range("Intersection of list1 and list2: ", result.begin(), res_end);

  return 0;
}
template<class InIter>
void show_range(const char *msg, InIter start, InIter end) {
  InIter itr;
  cout << msg << endl;
  for(itr = start; itr != end; ++itr)
    cout << *itr << endl;
}
  
    
  </source>


==Intersect two sets==


   
<source lang="cpp">  
#include <algorithm>
#include <iostream>
#include <vector>
using namespace std;

void print(int elem) {
  cout << elem << " ";
}
int main(int argc, char** argv) {
  vector<int> setOne, setTwo, setThree;
  setOne.push_back(1);
  setOne.push_back(2);
  setOne.push_back(3);
  
  setTwo.push_back(2);
  setTwo.push_back(3);
  setTwo.push_back(4);
  // set algorithms work on sorted ranges
  sort(setOne.begin(), setOne.end());
  sort(setTwo.begin(), setTwo.end());
  vector<int>::iterator  newEnd = set_intersection(setOne.begin(), setOne.end(), setTwo.begin(),setTwo.end(), setThree.begin());
  cout << "The intersection is: ";
  for_each(setThree.begin(), newEnd, &print);
  cout << endl;
  return (0);
}
  
    
  </source>


==Use set_intersection to intersect two lists==


   
<source lang="cpp">  
#include <algorithm>
#include <functional>
#include <iomanip>
#include <iostream>
#include <list>
#include <string>
#include <vector>
using namespace std;
class PC
{
   public:
   enum part { keyboard, mouse, monitor };
   PC( part a_part = PC::keyboard, int id = 0 );
   bool operator<( const PC& rhs ) const;
   void print() const;
   private:
   part part_;
   int id_;
};
inline
PC::PC( part a_part, int id ) : part_( a_part ), id_( id ){}
inline bool PC::operator<( const PC& rhs ) const{  
   return id_ < rhs.id_; 
}
void PC::print() const {
   string component;
   if( part_ == keyboard )
      component = "keyboard";
   else if( part_ == mouse )
      component = "mouse";
   else
      component = "monitor";
   cout << "ID: " << setw( 8 ) << left << id_ << " PC: " << component << endl;
}
int main( )
{
   list<PC> listA;
   listA.push_back( PC( PC::keyboard, 3 ) );
   listA.push_back( PC( PC::mouse, 1 ) );
   listA.push_back( PC( PC::monitor, 9 ) );
   listA.push_back( PC( PC::keyboard, 2 ) );
   listA.push_back( PC( PC::monitor, 8 ) );
   list<PC> inspector_B( listA );
   inspector_B.front() = PC( PC::mouse, 6 );
   inspector_B.back() = PC( PC::monitor, 1 );
   // must sort before using set algorithms
   listA.sort();
   inspector_B.sort();
   for_each( listA.begin(), listA.end(),mem_fun_ref( &PC::print ) );
   for_each( inspector_B.begin(), inspector_B.end(),mem_fun_ref( &PC::print ) );
   vector<PC> result;
   set_intersection( listA.begin(), listA.end(),inspector_B.begin(), inspector_B.end(),back_inserter( result ) );
   for_each( result.begin(), result.end(),mem_fun_ref( &PC::print ) );
}
  
    
  </source>