#152EasyStacks· Matching Pairs

Balanced Brackets Validator

A configuration linter must reject files whose brackets do not nest properly. You are given a string `s` that may contain letters, digits, spaces, punctuation and the six bracket characters `(` `)` `[` `]` `{` `}`. Decide whether the brackets are **balanced**: every opening bracket is closed by a bracket of the same kind, and brackets close in the reverse order in which they were opened, so `([)]` is invalid while `([])` is valid. All characters that are not brackets are ignored.

Input format

`s`: a string of printable ASCII characters (no double quotes or backslashes).

Output format

`true` if the brackets in `s` are balanced, otherwise `false`.

Examples

Input: s = "f(a[0]) + {b}"

Output: true

The round, square and curly pairs are each opened and closed in a consistent nesting, and the letters are ignored.

Input: s = "([)]"

Output: false

The square bracket closes while the round bracket opened after it is still open, so the nesting is crossed.

Input: s = "(("

Output: false

Both openers are never closed; a leftover opener is also an error.

Constraints

0 <= s.length <= 10^5
s contains printable ASCII characters only; it contains no double quote and no backslash.

#stack
#strings
#parsing