Given two strings s and t, determine if they are isomorphic.
Two strings 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
Note:
You may assume both s and t have the same length.
class Solution:
     def isIsomorphic(self, s1, s2):
         return len(set(zip(s1, s2))) == len(set(s1)) == len(set(s2))

class Solution:
     def isIsomorphic(self, s1, s2):
         return len(set(zip(s1, s2))) == len(set(s1)) == len(set(s2))
