function maze(m,n)

% Initialize
maze = ones(m,n)*15;
stack = zeros(m*n+1,1);

% Create
i = floor(rand*m+1);
j = floor(rand*n+1);

do
  if ( mod(floor(maze(i,j)/2^4),2) == 0 )
    maze(i,j) += 16;
  end
  vec = getUnvisited(maze,i,j);
  if ( vec(1) ~= 0 )
    index = (floor(rand*vec(1)+2));
    k = mod(vec(index),m)+1;
    l = floor(vec(index)/m)+1;
    maze = removeWall(maze,i,j,k,l);
    stack = push( stack, (j-1)*m+(i-1) );
    i = k;
    j = l;
  else
    [val,stack] = pop(stack);
    i = mod(stack(stack(1)+1),m)+1;
    j = floor(stack(stack(1)+1)/m)+1;
  end
until stack(1)==0

% Plot
plotMaze( maze, 10 );

end % mazesa


function vec = getUnvisited( maze, i, j )
  m = size(maze,1);
  n = size(maze,2);
  vec = zeros(5,1);
  for k=max(i-1,1):min(i+1,m)
    if ( mod(floor(maze(k,j)/2^4),2) == 0 )
      vec(1) += 1;
     vec(vec(1)+1) = (j-1)*m+(k-1);
   end
  end
  for l=max(j-1,1):min(j+1,n)
    if ( mod(floor(maze(i,l)/2^4),2) == 0 )
     vec(1) += 1;
     vec(vec(1)+1) = (l-1)*m+(i-1);
    end
  end % getUnvisited
end


function mz = removeWall(maze,i,j,k,l)
  if (k<i)&&(l==j)
    maze(i,j) -= 4;
    maze(k,l) -= 1;
  elseif (k>i)&&(l==j)
    maze(i,j) -= 1;
    maze(k,l) -= 4;
  elseif (k==i)&&(l<j)
    maze(i,j) -= 8;
    maze(k,l) -= 2;
  elseif (k==i)&&(l>j)
    maze(i,j) -= 2;
    maze(k,l) -= 8;
  endif
  mz = maze;
end % removeWall


function [val, s] = pop(stack)
  val = stack(stack(1)+1);
  stack(1) -= 1;
  s = stack;
end % pop


function s = push( stack, val ) 
  stack(1) += 1;
  stack(stack(1)+1) = val;
  s = stack;
end % push


function plotMaze( maze, cellSize )
  path = './';
  m = size(maze,1);
  n = size(maze,2);
  w = m*cellSize;
  h = n*cellSize;
  fout = fopen( strcat( path , 'maze.svg' ) ,'w');
  fprintf( fout ,'%s \n', '<?xml version="1.0" standalone="no"?>');
  fprintf( fout ,'%s \n', '<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN"');
  fprintf( fout ,'%s \n\n', '"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">');
  fprintf( fout ,'%s \n', '<svg width="100%" height="100%" version="1.1"');
  fprintf( fout ,'%s \n\n', 'xmlns="http://www.w3.org/2000/svg">');
  fprintf( fout ,'<polygon points="0,0 0,%d %d,%d %d,0" \n', h, w, h, w);
  fprintf( fout ,'%s \n', 'style="fill:#ffffff;');
  fprintf( fout ,'%s \n\n', 'stroke:black;stroke-width:3"/>');
  fprintf( fout ,'%s \n', '<path d="');
  xc = m/w;
  yc = n/h;
  for i = 1 : m
    for j = 1 : n
      if ( mod(floor(maze(i,j)/2^0),2) == 1 )
        fprintf( fout ,'M%8.2f %8.2f L%8.2f %8.2f \n', i/xc, (j-1)/yc, i/xc, j/yc );
      end  
      if ( mod(floor(maze(i,j)/2^1),2) == 1 )
        fprintf( fout ,'M%8.2f %8.2f L%8.2f %8.2f \n', (i-1)/xc, j/yc, i/xc, j/yc );
      end  
      if ( mod(floor(maze(i,j)/2^2),2) == 1 )
        fprintf( fout ,'M%8.2f %8.2f L%8.2f %8.2f \n', (i-1)/xc, (j-1)/yc, (i-1)/xc, j/yc );
      end  
      if ( mod(floor(maze(i,j)/2^3),2) == 1 )
        fprintf( fout ,'M%8.2f %8.2f L%8.2f %8.2f \n', (i-1)/xc, (j-1)/yc, i/xc, (j-1)/yc );
      end  
    end
  end
  fprintf( fout ,'%s \n', '"');
  fprintf( fout ,'%s \n', 'style="stroke:black;stroke-width:.5"/>');
  fprintf( fout ,'%s \n', '</svg>');
  fclose(fout);
end %plotMaze