Image you are buliding a compiler. Before running any code, the compiler must check that the parentheses in the program are balanced.

Every opening bracket must have a corresponding closing bracket. We can approximate this using strings.

Given a string containing just the characters ‘(’, ‘)’, ‘{’, ‘}’, ‘[’ and ‘]’, determine if the input string is valid.

An input string is valid if:

• open brackets are closed by the same type of brackets.
• open brackets are closed in the correct order.
• Note that an empty string is also considered valid.

Example:

Input: “((()))” Output: True

Input: “[()]{}” Output: True

Input: “({[)]” Output: False

class Solution:
  def isValid(self, s):
    # TODO::

assert False, Solution.isValid("()(){(())")
assert True, Solution.isValid("")
assert True, Solution.isValid("([{}])()")