iframe-proxy | Sunbelt Computer Software

33 lines (26 loc) · 844 Bytes

import unittest

class Solution:

PARENTHESES = {

")": "(",

"}": "{",

"]": "[",

}

def is_valid(self, s: str) -> bool:

stack = []

for c in s:

if c not in self.PARENTHESES:

stack.append(c)

else:

if not stack or stack.pop() != self.PARENTHESES[c]:

return False

return len(stack) == 0

class Test(unittest.TestCase):

def test_is_valid(self):

solution = Solution()

self.assertEqual(solution.is_valid("()"), True)

self.assertEqual(solution.is_valid("()[]{}"), True)

self.assertEqual(solution.is_valid("(}"), False)

self.assertEqual(solution.is_valid("["), False)

self.assertEqual(solution.is_valid("]"), False)

if __name__ == "__main__":

unittest.main()

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