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author | Vincent Ambo <mail@tazj.in> | 2021-12-13T22·51+0300 |
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committer | Vincent Ambo <mail@tazj.in> | 2021-12-13T23·15+0300 |
commit | 019f8fd2113df4c5247c3969c60fd4f0e08f91f7 (patch) | |
tree | 76a857f61aa88f62a30e854651e8439db77fd0ea /users/wpcarro/scratch/data_structures_and_algorithms/bracket-validator.py | |
parent | 464bbcb15c09813172c79820bcf526bb10cf4208 (diff) | |
parent | 6123e976928ca3d8d93f0b2006b10b5f659eb74d (diff) |
subtree(users/wpcarro): docking briefcase at '24f5a642' r/3226
git-subtree-dir: users/wpcarro git-subtree-mainline: 464bbcb15c09813172c79820bcf526bb10cf4208 git-subtree-split: 24f5a642af3aa1627bbff977f0a101907a02c69f Change-Id: I6105b3762b79126b3488359c95978cadb3efa789
Diffstat (limited to 'users/wpcarro/scratch/data_structures_and_algorithms/bracket-validator.py')
-rw-r--r-- | users/wpcarro/scratch/data_structures_and_algorithms/bracket-validator.py | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/users/wpcarro/scratch/data_structures_and_algorithms/bracket-validator.py b/users/wpcarro/scratch/data_structures_and_algorithms/bracket-validator.py new file mode 100644 index 000000000000..a50f8b074e55 --- /dev/null +++ b/users/wpcarro/scratch/data_structures_and_algorithms/bracket-validator.py @@ -0,0 +1,63 @@ +import unittest + + +################################################################################ +# Solution +################################################################################ +# is_valid :: String -> Boolean +def is_valid(xs): + s = [] + seeking = { + '}': '{', + ']': '[', + ')': '(', + } + openers = seeking.values() + closers = seeking.keys() + for c in xs: + if c in openers: + s.append(c) + elif c in closers: + if not s: + return False + elif s[-1] != seeking.get(c): + return False + else: + s.pop() + return len(s) == 0 + + +################################################################################ +# Tests +################################################################################ +class Test(unittest.TestCase): + def test_valid_short_code(self): + result = is_valid('()') + self.assertTrue(result) + + def test_valid_longer_code(self): + result = is_valid('([]{[]})[]{{}()}') + self.assertTrue(result) + + def test_interleaved_openers_and_closers(self): + result = is_valid('([)]') + self.assertFalse(result) + + def test_mismatched_opener_and_closer(self): + result = is_valid('([][]}') + self.assertFalse(result) + + def test_missing_closer(self): + result = is_valid('[[]()') + self.assertFalse(result) + + def test_extra_closer(self): + result = is_valid('[[]]())') + self.assertFalse(result) + + def test_empty_string(self): + result = is_valid('') + self.assertTrue(result) + + +unittest.main(verbosity=2) |