#include <iostream>
#include <cstdlib>
#include <ctime>
#include <set>

using namespace std;

class Coord
{
public:
  Coord(int px, int py) : x(px), y(py) {}
  bool operator<(Coord c) const { return x < c.x || (x == c.x && y < c.y); }
  Coord operator*(int n) const { return Coord(x*n, y*n); }

  void center(Coord const& c);
  
private:
  int x;
  int y;
};

// Small utility function to calculate the number right between 'a' and 'b'
int middle_number(int a, int b)
{
  return (a + b) / 2;
}

// Move the current coordinate half distance toward 'c'
void Coord::center(Coord const& c)
{
  x = middle_number(x, c.x);
  y = middle_number(y, c.y);
}

int main()
{
  int size;
  int count;
  
  cout << "Enter figure size: ";
  cin >> size;
  
  cout << "Enter step count: ";
  cin >> count;

  srand(time(nullptr));
  
  Coord corner[3] = { Coord(0,0), Coord(0,1), Coord(1,0) };
  set<Coord> filled;
  Coord current(rand() % size, rand() % size);

  // Calculate the coordinates in the sierpinski set (approximate)
  for (int i = 0; i < count; ++i)
  {
    current.center(corner[rand() % 3]*size);
    filled.insert(current);
  }

  // Plot the coordinate to see the figure
  for (int r = 0; r < size; ++r)
  {
    for (int c = 0; c < size; ++c)
    {
      if ( filled.find({c,r}) != filled.end() )
        cout << '/';
      else
        cout << ' ';
    }
    cout << endl;
  }
  cout << endl;

  return 0;
}