Подсчет расстояния от точки до клетки вороного

#include <iostream>
#include <vector>
 
#include <boost/geometry.hpp>
#include <boost/geometry/geometries/polygon.hpp>
#include <boost/polygon/voronoi.hpp>
namespace bg = boost::geometry;
 
using boost::polygon::voronoi_diagram;
typedef voronoi_diagram<double>::cell_type cell_type;
typedef voronoi_diagram<double>::edge_type edge_type;
typedef voronoi_diagram<double>::vertex_type vertex_type;
typedef boost::polygon::point_data<double> point_type;
 
using namespace std;
 
int main() {
 
  vector< point_type > vpoints;
  vpoints.push_back(point_type(0.0, 0.0));
  vpoints.push_back(point_type(0.0, 4.0));
  vpoints.push_back(point_type(4.0, 4.0));
  vpoints.push_back(point_type(4.0, 0.0));
  vpoints.push_back(point_type(2.0, 2.0));
 
  vector< point_type > qpoints;
  qpoints.push_back(point_type(0.0, 0.0));
  qpoints.push_back(point_type(0.0, 2.0));
  qpoints.push_back(point_type(3.0, 3.0));
  qpoints.push_back(point_type(5.0, 5.0));
  qpoints.push_back(point_type(5.0, 5.0));
 
  voronoi_diagram<double> vd;
  construct_voronoi(vpoints.begin(), vpoints.end(), &vd);
 
  for (int i = 0; i < qpoints.size(); i++) {
    for (voronoi_diagram<double>::const_cell_iterator it = vd.cells().begin();
         it != vd.cells().end(); ++it) {
      if (i == it->source_index()) {
        cout << "v[i]=(" << vpoints[i].x() << "," << vpoints[i].y() << ")\t";
        cout << "q[i]=(" << qpoints[i].x() << "," << qpoints[i].y() << ")\t";
        cout << "Distance=";
        cout << bg::distance(qpoints[i], *it) << endl;
        cout << endl;
        break;
      }
    }
  }
 
  return 0;
}