using ds in cpp OpenGL file

main.cpp

/*

TO COMPILE & RUN 

 g++ -o out main.cpp -framework GLUT -framework OpenGL -Wno-deprecated && ./out

*/

#ifdef __APPLE__
#include <GLUT/glut.h>
#include <OpenGL/gl.h>
#include <OpenGL/glu.h>
#else
#include <GL/glut.h>
#include <GL/glu.h>
#include <GL/gl.h>
#endif

#include <iostream> 
#include <list> 
#include <iterator> 
using namespace std; 
  
//function for printing the elements in a list 
void showlist(list <int> g) 
{ 
    list <int> :: iterator it; 
    for(it = g.begin(); it != g.end(); ++it) 
        cout << '\t' << *it; 
    cout << '\n'; 
}

void Display();

int main(int argc, char** argr) {
  glutInit(&argc, argr);
  glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
  glutInitWindowSize(500, 500);
  glutInitWindowPosition(50, 50);
  glutCreateWindow("Lab 01");
  glutDisplayFunc(Display);
  glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
  glPointSize(9.0);
  //glLineWidth(9.0);
  gluOrtho2D(0.0, 1000.0, 0.0, 600.0);
  glutMainLoop();
}

void Display() {
  glClear(GL_COLOR_BUFFER_BIT);


  list <int> gqlist1, gqlist2; 
  
  
  for (int i = 0; i < 10; ++i) 
  { 
      gqlist1.push_back(i * 2); 
      gqlist2.push_front(i * 3); 
  } 
  cout << "\nList 1 (gqlist1) is : "; 
  showlist(gqlist1); 

  cout << "\nList 2 (gqlist2) is : "; 
  showlist(gqlist2); 

  cout << "\ngqlist1.front() : " << gqlist1.front(); 
  cout << "\ngqlist1.back() : " << gqlist1.back(); 

  cout << "\ngqlist1.pop_front() : "; 
  gqlist1.pop_front(); 
  showlist(gqlist1); 

  cout << "\ngqlist2.pop_back() : "; 
  gqlist2.pop_back(); 
  showlist(gqlist2); 

  cout << "\ngqlist1.reverse() : "; 
  gqlist1.reverse(); 
  showlist(gqlist1); 

  cout << "\ngqlist2.sort(): "; 
  gqlist2.sort(); 
  showlist(gqlist2); 


  glFlush();
}