valid-parentheses.md

Intuition

Approach

Complexity

• Time complexity:

• Space complexity:

Code

VALID_CHARS = {
  '(' => ')',
  '{' => '}',
  '[' => ']',
}

# @param {String} s
# @return {Boolean}
def is_valid(s)
  chars = s.split('')
  return false if chars.size < 2
  openTags = []

  result = chars.all? do |c|
    if VALID_CHARS.keys.include?(c)
      openTags << c
      true
    else
      res = VALID_CHARS[openTags.last] == c
      openTags.pop if res
      res
    end
  end

  result && openTags.empty?
end