1.4solution.py

# O(N)
import unittest

def pal_perm(phrase):
	'''function checks if a string is a permutation of a palindrome or not'''
	table = [0 for _ in range(ord('z') - ord('a') + 1)]
	countodd = 0
	for c in phrase:
		x = char_number(c)
		if x != -1:
			table[x] += 1
			if table[x] % 2:
				countodd += 1
			else:
				countodd -= 1

	return countodd <= 1

def char_number(c):
	a = ord('a')
	z = ord('z')
	A = ord('A')
	Z = ord('Z')
	val = ord(c)

	if a <= val <= z:
		return val - a
	elif A <= val <= Z:
		return val - A
	return -1


class Test(unittest.TestCase):
	'''Test Cases'''
	data = [
	    ('Tact Coa', True),
	    ('jhsabckuj ahjsbckj', True),
	    ('Able was I ere I saw Elba', True),
	    ('So patient a nurse to nurse a patient so', False),
	    ('Random Words', False),
	    ('Not a Palindrome', False),
	    ('no x in nixon', True),
	    ('azAZ', True)]

	def test_pal_perm(self):
		for [test_string, expected] in self.data:
			actual = pal_perm(test_string)
			self.assertEqual(actual, expected)

if __name__ == "__main__":
	unittest.main()