brackets.py

def is_balanced(exp: AnyStr) -> bool:
    """
    Time Complexity: O(n)
    Space complexity: O(n)

    >>> s = "()[]{}"
    >>> is_balanced(s)
    True

    >>> s = "([)]"
    >>> is_balanced(s)
    False

    >>> s = "{[]}"
    >>> is_balanced(s)
    True

    >>> s = "()"
    >>> is_balanced(s)
    True
    """
    opening = ["(", "[", "{"]
    closing = [")", "]", "}"]
    mapping = dict(zip(closing, opening))
    stack = []
    for char in exp:
        if char in closing:
            if not stack or stack[-1] != mapping[char]:
                return False
            stack.pop()
        else:
            stack.append(char)
    return not stack