input: Write a function to construct a pattern of asterisks and return it as a list of strings, each string representing a line in the pattern.
  assert construct_pattern(3) == ["*", "**", "***", "**", "*"]
  assert construct_pattern(5) == ["*", "**", "***", "****", "*****", "****", "***", "**", "*"]
  assert construct_pattern(1) == ["*"]
output: def construct_pattern(n):
      pattern = []
      for i in range(1, n + 1):
          pattern.append('*' * i)
      for i in range(n - 1, 0, -1):
          pattern.append('*' * i)
      return pattern