93d654df77
Write a predicate to test whether any permutation of an input string is a palindrome.
37 lines
1 KiB
Python
37 lines
1 KiB
Python
import unittest
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from collections import Counter
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def has_palindrome_permutation(xs):
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vs = Counter(xs).values()
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return len([v for v in vs if v % 2 == 1]) in {0, 1}
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# Tests
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class Test(unittest.TestCase):
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def test_permutation_with_odd_number_of_chars(self):
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result = has_palindrome_permutation('aabcbcd')
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self.assertTrue(result)
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def test_permutation_with_even_number_of_chars(self):
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result = has_palindrome_permutation('aabccbdd')
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self.assertTrue(result)
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def test_no_permutation_with_odd_number_of_chars(self):
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result = has_palindrome_permutation('aabcd')
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self.assertFalse(result)
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def test_no_permutation_with_even_number_of_chars(self):
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result = has_palindrome_permutation('aabbcd')
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self.assertFalse(result)
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def test_empty_string(self):
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result = has_palindrome_permutation('')
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self.assertTrue(result)
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def test_one_character_string(self):
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result = has_palindrome_permutation('a')
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self.assertTrue(result)
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unittest.main(verbosity=2)
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