Solve InterviewCake permutation-palindrome problem

Write a predicate to test whether any permutation of an input string is a
palindrome.
This commit is contained in:
William Carroll 2020-02-24 16:24:16 +00:00
parent 6249e19cdc
commit 93d654df77
2 changed files with 38 additions and 1 deletions

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import unittest
from collections import Counter
def has_palindrome_permutation(xs):
vs = Counter(xs).values()
return len([v for v in vs if v % 2 == 1]) in {0, 1}
# Tests
class Test(unittest.TestCase):
def test_permutation_with_odd_number_of_chars(self):
result = has_palindrome_permutation('aabcbcd')
self.assertTrue(result)
def test_permutation_with_even_number_of_chars(self):
result = has_palindrome_permutation('aabccbdd')
self.assertTrue(result)
def test_no_permutation_with_odd_number_of_chars(self):
result = has_palindrome_permutation('aabcd')
self.assertFalse(result)
def test_no_permutation_with_even_number_of_chars(self):
result = has_palindrome_permutation('aabbcd')
self.assertFalse(result)
def test_empty_string(self):
result = has_palindrome_permutation('')
self.assertTrue(result)
def test_one_character_string(self):
result = has_palindrome_permutation('a')
self.assertTrue(result)
unittest.main(verbosity=2)

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** DONE Cafe Order Checker
* Hashing and hash tables
** DONE Inflight Entertainment
** TODO Permutation Palindrome
** DONE Permutation Palindrome
** TODO Word Cloud Data
** TODO Top Scores
* Greedy Algorithms