// test_set2.cc    just demo some features, using 'inserter'

#include <iostream>
#include <algorithm>   // needed for set_  algorithms
#include <set>
using namespace std;

typedef set<int> my_set;
           // give my typename to a set of integers
           // this simplifies code for function prototypes, etc.
                              
void put(my_set S)  // function to output a set, default order
{
  cout << "S(" << S.size() << ")= ";  // use begin() and end() to be safe 
  for(my_set::const_iterator p=S.begin(); p!=S.end(); p++) cout << *p << " ";
  cout << endl;  
}

int main()
{
  my_set A;            // construct an empty sets
  my_set B;
  my_set C;
  my_set D;
  my_set D1;
  my_set D2;
  my_set D3;
  my_set::const_iterator p; // scratch pointer for 'find'

  cout << "test_set2 running, S is "
       << (C.empty() ? "empty" : "has junk") << endl;
  cout << C.size() << "=size of C, max=" << C.max_size() << endl;

  A.insert(3);
  A.insert(5);
  A.insert(1);
  B.insert(1);
  B.insert(2);
  B.insert(3);

  cout << "initial A        ";
  put(A);     // begin()  end()  size() used in 'put()' 
  
  cout << "initial B        ";
  put(B);
  
  set_intersection(A.begin(), A.end(), B.begin(), B.end(),
		   inserter(C,C.begin()));

  cout << "intersection A B ";
  put(C);

  set_union(A.begin(), A.end(), B.begin(), B.end(),
            inserter(D,D.begin()));
  cout << "union A B        ";
  put(D);
  

  set_difference(A.begin(), A.end(), B.begin(), B.end(),
                 inserter(D1,D1.begin()));
  cout << "difference A-B   ";
  put(D1);
  

  set_difference(B.begin(), B.end(), A.begin(), A.end(),
                 inserter(D2,D2.begin()));
  cout << "difference B-A   ";
  put(D2);
  

  set_symmetric_difference(A.begin(), A.end(), B.begin(), B.end(),
                           inserter(D3,D3.begin()));
  cout << "sym diff A B     ";
  put(D3);

  cout << "C = D            ";
  C = D;
  put(C);
  
  cout << "first in set     " << *D.begin() << endl;
  D.erase(D.begin());
  cout << "erased first     ";
  put(D);

  p = D.find(3);  // remember, it returns a pointer, not a value
  cout << "D.find(3) found  " << *p << endl;

  p = D.find(4);
  cout << "D.find(4)        " << (p==D.end()? "not found" : "4" /* *i */)
       << endl;

  cout << "test_set2 finished" << endl;
  
  return 0;
}

// Output of this program is:
// test_set2 running, S is empty
// 0=size of C, max=4294967295
// initial A        S(3)= 1 3 5 
// initial B        S(3)= 1 2 3 
// intersection A B S(2)= 1 3 
// union A B        S(4)= 1 2 3 5 
// difference A-B   S(1)= 5 
// difference B-A   S(1)= 2 
// sym diff A B     S(2)= 2 5 
// C = D            S(4)= 1 2 3 5 
// first in set     1
// erased first     S(3)= 2 3 5 
// D.find(3) found  3
// D.find(4)        not found
// test_set2 finished