diff --git a/valid-parentheses/JustHm.swift b/valid-parentheses/JustHm.swift new file mode 100644 index 000000000..3b400ad39 --- /dev/null +++ b/valid-parentheses/JustHm.swift @@ -0,0 +1,24 @@ +// time: O(n) space: O(n) +class Solution { + func isValid(_ s: String) -> Bool { + var answer = [Character]() + for char in s { + if let recent = answer.last { + if char == ")" && recent == "(" { + answer.removeLast() + continue + } + else if char == "]" && recent == "[" { + answer.removeLast() + continue + } + else if char == "}" && recent == "{" { + answer.removeLast() + continue + } + } + answer.append(char) + } + return answer.isEmpty + } +}