[Leetcode] 205. Isomorphic Strings

https://leetcode.com/problems/isomorphic-strings

class Solution:
    def isIsomorphic(self, s: str, t: str) -> bool:

        mapping = {}

        for i, c in enumerate(s):
            if mapping.get(c, None) is None:
                if t[i] in mapping.values():
                    return False
                mapping[c] = t[i]
            else:
                if mapping[c] != t[i]:
                    return False

        return True