compareVersion.py

import unittest

class Solution(object):

    def compareVersion(self, version1, version2):
        """
        Compares two version numbers version1 and version2.
        If version1 > version2 return 1, if version1 < version2 return -1,
        otherwise return 0.

        Assumes that the version strings are non-empty and contain only
        digits and the . character. The . character does not represent a
        decimal point and is used to separate number sequences. For
        instance, 2.5 is not "two and a half" or "half way to version three",
        it is the fifth second-level revision of the second first-level
        revision. Assumes only 4 levels of the revisions.

        :type version1: str
        :type version2: str
        :rtype: int
        """

        matchedVersion1 = version1.split(".")
        matchedVersion2 = version2.split(".")

        for i in range(0, 3):
            elemVersion1 = matchedVersion1[i:i+1] or 0
            elemVersion2 = matchedVersion2[i:i+1] or 0
            if elemVersion1 < elemVersion2:
                return -1
            if elemVersion1 > elemVersion2:
                return 1
        return 0

class TestSolution(unittest.TestCase):
    solution = Solution()

    def test_single_less(self):
        self.assertEqual(self.solution.compareVersion("1", "2"), -1)

    def test_single_more(self):
        self.assertEqual(self.solution.compareVersion("2", "1"), 1)

    def test_single_equal(self):
        self.assertEqual(self.solution.compareVersion("1", "1"), 0)

    def test_double_less(self):
        self.assertEqual(self.solution.compareVersion("1.2", "2.3"), -1)

    def test_double_more(self):
        self.assertEqual(self.solution.compareVersion("2.2", "1.4"), 1)

    def test_double_equal(self):
        self.assertEqual(self.solution.compareVersion("1.1", "1.1"), 0)

    def test_double_and_triple_version(self):
        self.assertEqual(self.solution.compareVersion("1.1", "1.1.2"), -1)

    def test_quadruple_and_double_version(self):
        self.assertEqual(self.solution.compareVersion("1.0.0.0", "1.0.0"), 0)

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