d4d8397e5f
Adds some of the code I generated while studying for a role transfer at Google using the fantastic resource, InterviewCake.com. This work predates the mono-repo. I should think of ways to DRY up this code and the code in crack_the_coding_interview, but I'm afraid I'm creating unnecessary work for myself that way.
63 lines
1.6 KiB
Python
63 lines
1.6 KiB
Python
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)
|