Cannot access public method from another class

I have the following classes:

class Point
{
    private:
        Vector2d _coordinates;
        int _label;
    public:
        
        Point(const double x = 0.0, const double y = 0.0);
        Point(Vector2d coordinates);

        void setCoordinates(const double x, const double y) {_coordinates(x, y);}
        const Vector2d& getCoordinates() const {return _coordinates;}
        int getPointLabel() const{ return _label;}
        void setPointLabel(int label);
   

class PolygonCutter
{ 
//output parameters
         vector<Point> _newPoints;
         vector< vector<Point>> _cuttedPolygons; 

 public:
        
 
        void AddLabels(const vector<Point> &points, const vector<const unsigned int>&polygonVertices);
};

I working on PolygonCutter. i need it to be just a manager that uses a methodAddLabels to set the member _label of each Point in vector points to the integers passed as the vector polygonVertices How can I do it? I am having trouble because I am not able to access the method setPointLabel(int label) from here:

My try contains the following errors:

void AddLabels(const vector<Point> &points, const vector<const unsigned int>&polygonVertices);
{
    int originalNumberOfVertices = points.size();
    for(int i = 0; i<originalNumberOfVertices ; i++)
    {   int label = polygonVertices[i]; // ERROR type 'const vector<const unsigned int>' does not provide a subscript operator
        const Point& point = points[i];
        point.setPointLabel(label); // ERROR 'this' argument to member function 'setPointLabel' has type 'const Point', but function is not marked const                                                           
    }
}

Answer

in AddLabels method, vector points is const. setPointLabel is non-const member function. non-const member functions can only be invoked for non-const objects. Either

  1. remove const from const vector &points , or
  2. mark function setPointLabel const.