/// This program demonstrates the assign operator. It then times the assign operator, relative to a for loop

#include <iostream>
#include <iterator>
#include <vector>
#include <boost/timer.hpp>

using namespace std;

const int Niter = 100000;

int main() {
  int i, j;
  vector<int> l1, l2, l3;
  boost::timer t;
  double tm;

  for (i=-10;i<0;i++) {
    l1.push_back( i);
  }

  for (;i<10;i++) {
    l2.push_back( i);
  }

  l3 = l1;

  l3.assign( l2.begin() + l2.size()/2, l2.end());

  ostream_iterator<int> output(cout);

  cout << "l3 should equal 56789" << endl;
  cout << "l3 = " ;
  copy( l3.begin(), l3.end(), output);
  cout << endl;

  t.restart();
  for (i=0; i<Niter; i++) {
    l3.assign( l2.begin() + l2.size()/2, l2.end());
  }
  tm = t.elapsed();
  cout << "assign takes " << tm << " seconds" << endl;

  t.restart();
  for (i=0; i<Niter; i++) {
    l3.clear();
    for (j=l2.size()/2; j<l2.size(); j++) {
      l3.push_back( l2[j]);
    }
  }
  tm = t.elapsed();
  cout << "for loop takes " << tm << " seconds" << endl;

  return 0;
}