'''
Level: Easy

Given two strings s and t, determine if they are isomorphic.

Two strings s and t are isomorphic if the characters in s can be replaced to get t.

All occurrences of a character must be replaced with another character while preserving

the order of characters. No two characters may map to the same character,

but a character may map to itself.



Example 1:

Input: s = "egg", t = "add"
Output: true

Example 2:

Input: s = "foo", t = "bar"
Output: false

Example 3:

Input: s = "paper", t = "title"
Output: true


Constraints:

1 <= s.length <= 5 * 104
t.length == s.length
s and t consist of any valid ascii character.


'''
class Solution(object):
    def isIsomorphic(self, s, t):
        """
        :type s: str
        :type t: str
        :rtype: bool
        """

        dict_s = {}
        dict_t = {}

        for i in range(len(s)):
            if s[i] not in dict_s:
                dict_s[s[i]] = t[i]
            else:
                if dict_s[s[i]] != t[i]:
                    return False

            if t[i] not in dict_t:
                dict_t[t[i]] = s[i]
            else:
                if dict_t[t[i]] != s[i]:
                    return False

        return True






s = "egg"
t = "add"
assert True == Solution().isIsomorphic(s, t)

s = "foo"
t = "bar"
assert False == Solution().isIsomorphic(s, t)

s = "bbbaaaba"
t = "aaabbbba"
assert False == Solution().isIsomorphic(s, t)

s = "badc"
t = "baba"
assert False == Solution().isIsomorphic(s, t)