Check if Strings Can be Made Equal With Operations II — Python

# Time:  O(n)
# Space: O(1)

import collections


# freq table
class Solution(object):
    def checkStrings(self, s1, s2):
        """
        :type s1: str
        :type s2: str
        :rtype: bool
        """
        return all(collections.Counter(s1[j] for j in xrange(i, len(s1), 2)) == collections.Counter(s2[j] for j in xrange(i, len(s2), 2)) for i in xrange(2))