input: Write a function to generate the first n elements of the Sierpinski triangle. If n is greater than 0, the function should print a visual representation of the Sierpinski triangle up to the n-th level. If n is 0, the function should print a single space.
  def sierpinski_triangle(n): 
      if n == 0: 
          print(" ") 
          return 
      
      # Initialize the buffer with spaces
      buffer = [' ' * (2 ** n)] 
      
      # Recursively fill the buffer with '1's at the appropriate positions
      def fill(y, x, size): 
          if size == 1: 
              buffer[y][x] = '1' 
          else: 
              new_size = size // 2 
              fill(y, x, new_size) 
              fill(y + new_size, x - new_size, new_size) 
              fill(y + new_size, x + new_size, new_size) 
      
      fill(0, 2 ** (n - 1), 2 ** (n - 1)) 
      
      # Print the buffer
      for line in buffer: 
          print(line) 
  
  assert sierpinski_triangle(0) == " " 
  assert sierpinski_triangle(1) == "1" 
  assert sierpinski_triangle(2) == " 1 \n1 1\n  1  " 
  assert sierpinski_triangle(3) == "   1   \n  1 1  \n 1   1 \n1 1 1 1\n       1   " 
  assert sierpinski_triangle(6) == "             1             \n            1 1            \n           1   1           \n          1 1 1 1          \n         1       1         \n        1 1     1 1        \n       1   1   1   1       \n      1 1 1 1 1 1 1 1      \n     1               1     \n    1 1             1 1    \n   1   1           1   1   \n  1 1 1 1         1 1 1 1  \n 1       1       1       1 \n1 1     1 1     1 1     1 1\n       1   1   1   1       \n      1 1 1 1 1 1 1 1      \n     1               1     \n    1 1             1 1    \n   1   1           1   1   \n  1 1 1 1         1 1 1 1  \n 1       1       1       1 \n1 1     1 1     1 1     1 1\n       1   1   1   1       \n      1 1 1 1 1 1 1 1      \n     1               1     \n    1 1             1 1    \n   1   1           1   1   \n  1 1 1 1         1 1 1 1  \n 1       1       1       1 \n1 1     1 1     1 1     1 1"
output: def sierpinski_triangle(n): 
      if n == 0: 
          print(" ") 
          return 
      
      buffer = [[' ' for _ in range(2 ** n)] for _ in range(2 ** n)]
      
      def fill(y, x, size): 
          if size == 1: 
              buffer[y][x] = '1' 
          else: 
              new_size = size // 2 
              fill(y, x, new_size) 
              fill(y + new_size, x - new_size, new_size) 
              fill(y + new_size, x + new_size, new_size) 
      
      fill(0, 2 ** (n - 1), 2 ** (n - 1)) 
      
      for line in buffer: 
          print(''.join(line))