ctci/Chapter 1 Arrays and strings/1.2. check_permutation.py

47 lines
1.2 KiB
Python

import unittest
def check_permutation(s1, s2):
if len(s1) != len(s2):
return False
checker = dict()
for char in s1:
ascii_val = ord(char)
if ascii_val not in checker:
checker[ascii_val] = 1
else:
checker[ascii_val] += 1
for char in s2:
ascii_val = ord(char)
if ascii_val not in checker:
return False
checker[ascii_val] -= 1
if checker[ascii_val] == 0:
del checker[ascii_val]
if checker[ascii_val] < 0:
return False
if checker == {}:
return True
else:
return False
class Test(unittest.TestCase):
dataT = [('abcd', 'dbca'), ('dfgh', 'dfgh'), ('', '')]
dataF = [('aane', 'anee'), ('ab', 'ca'), ('ane', 'aane')]
def test(self):
# true check
for test_string in self.dataT:
s1, s2 = test_string
res = check_permutation(s1, s2)
self.assertTrue(res)
# false check
for test_string in self.dataF:
s1, s2 = test_string
res = check_permutation(s1, s2)
self.assertFalse(res)
if __name__ == "__main__":
unittest.main()