input: Write a function to determine if a string `s` has matching parentheses. A string has matching parentheses if every opening parenthesis `(` has a corresponding closing parenthesis `)` and they are in the correct order. If the string has matching parentheses, return True; otherwise, return False.
  
  assert matching_paren("(())")==True
  assert matching_paren("(()")==False
  assert matching_paren("(()))")==False
  assert matching_paren("((()))")==True
  assert matching_paren("")==True
output: def matching_paren(s):
      count = 0
      for char in s:
          if char == '(':
              count += 1
          elif char == ')':
              count -= 1
          if count < 0:
              return False
      return count == 0