// This is a simple code to generate Julia sets of quadratic functions
// of the form f(z) = z^2 + c.
//
// The algorithm used is the Modified Inverse Iteration Method described in
// 
//   Heinz-Otto Peitgen, Dietmar Saupe, eds., The Science of Fractal Images
//   Springer-Verlag, New York, 1988. pp. 178
//   ISBN 0-387-96608-0
//
// More information and Mathematica code, can be found at:
//
// http://facstaff.unca.edu/mcmcclur/professional/Julia/index.html
//

#include <iostream>
#include <cassert>
#include <cmath>
#include <vector>

using namespace std;

double rand_unit() {
  return( ((double)rand())/RAND_MAX );
}

double rand_interval(double a, double b) {
  return( a+(b-a)*rand_unit() );
}

void inverse_step(double wx,
		  double wy,
		  vector< vector<int> >& grid,
		  const double cx,
		  const double cy,
		  const int Nmax,
		  const int res,
		  const int depth,
		  const int maxdepth) {

  // Check for end of recursion
  if(depth >= maxdepth) return;
  
  // This point is good, so write it out
  cout << wx << ' ' << wy << endl;
  
  double r, theta;
  int xneg, yneg, xpos, ypos; // grid coordinates
  
  // convert to polar coordinates
  r = sqrt((wx-cx)*(wx-cx) + (wy-cy)*(wy-cy));
  theta = atan2(wy-cy,wx-cx);
  
  // find inverse using f^(-1)(w) = +/-sqrt(w - c)
  wx = sqrt(r)*cos(theta/2.0);
  wy = sqrt(r)*sin(theta/2.0);

  // translate complex plane coordinates to grid coordinates
  xpos = static_cast<int>(floor( (res*(wx + 2.0))/4.0) );
  ypos = static_cast<int>(floor( (res*(wy + 2.0))/4.0) );
  xneg = static_cast<int>(floor( (res*(-wx + 2.0))/4.0) );
  yneg = static_cast<int>(floor( (res*(-wy + 2.0))/4.0) );
  
  if(grid[xpos][ypos] < Nmax){
    grid[xpos][ypos]++;
    inverse_step(wx,wy,grid,cx,cy,Nmax,res,depth+1,maxdepth);
  }
  if(grid[xneg][yneg] < Nmax){
    grid[xneg][yneg]++;
    inverse_step(-wx,-wy,grid,cx,cy,Nmax,res,depth+1,maxdepth);
  }
}
  

int main(int argc, char* argv[]){

  double cx, cy; // real and imaginary parts of c parameter
  double wx, wy; // real and imaginary parts of iterated value
  int Nmax;      // max number of points per grid box
  int res;       // resolution of the grid
  int maxdepth;  // maximum depth of tree search

  srand(time(NULL)); // seed the random number generator with the system clock

  cin >> cx >> cy >> Nmax >> res >> maxdepth;

  assert(Nmax > 0);
  assert(res>=10);
  assert((res%2)==0);
  assert(maxdepth>0);

  // The grid ranges from -2...+2 in both the x and y directions
  vector< vector<int> > grid;
  vector<int> empty_row(res, 0);
  for(int i=0; i<res; ++i)
    grid.push_back(empty_row);

  // Randomly pick a point somewhat near the origin with which
  // to start iterating.
  wx = rand_interval(-1.0, 1.0);
  wy = rand_interval(-1.0, 1.0);

  double r, theta;
  double sign;
  int xneg, yneg, xpos, ypos; // grid coordinates

  // Quickly do some iterations randomly picking one of the roots so
  // that we get close to J_c before selectively picking roots.
  int i=0;
  while(i<50){
    // original function  f(z) = z^2 + c
    // inverse function   f^(-1)(w) = +/-sqrt(w - c)
    r = sqrt((wx-cx)*(wx-cx) + (wy-cy)*(wy-cy));
    theta = atan2(wy-cy,wx-cx);

    sign = (rand_unit() < 0.5) ? -1.0 : 1.0;
    wx = sign*sqrt(r)*cos(theta/2.0);
    wy = sign*sqrt(r)*sin(theta/2.0);

    ++i;
  }
  
  xpos = static_cast<int>(floor( (res*(wx + 2.0))/4.0) );
  ypos = static_cast<int>(floor( (res*(wy + 2.0))/4.0) );
  xneg = static_cast<int>(floor( (res*(-wx + 2.0))/4.0) );
  yneg = static_cast<int>(floor( (res*(-wy + 2.0))/4.0) );
  
  grid[xpos][ypos]++;
  inverse_step(wx,wy,grid,cx,cy,Nmax,res,0,maxdepth);
  
  grid[xneg][yneg]++;
  inverse_step(-wx,-wy,grid,cx,cy,Nmax,res,0,maxdepth);
    
  return 0;
}

