Compare two version numbers version1 and version2.

If version1 > version2 return 1, if version1 < version2 return -1, otherwise return 0.

You may assume 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.

Here is an example of version numbers ordering:

Solution:

class Solution(object):
    def compareVersion(self, version1, version2):
        """
        :type version1: str
        :type version2: str
        :rtype: int
        """
        def compare(x, y, i):
            if len(x) <= i and len(y) <= i:
                return 0
            elif len(x) <=i and len(y) > i:
                x.append("0")
                return compare(x, y, i)
            elif len(x) > i and len(y) <= i:
                y.append("0")
                return compare(x, y, i)
            elif int(x[i]) > int(y[i]):
                return 1
            elif int(y[i]) > int(x[i]):
                return -1
            else:
                return compare(x, y, i+1)
        v1 = version1.split(".")
        v2 = version2.split(".")
        return compare(v1, v2, 0)