205. Isomorphic Strings

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.



def isIsomorphic(s: str, t: str):
       
    charMap = {}
   
    L = len(s)
   
    for i in range(L):
        if s[i] not in charMap:
            if t[i] not in charMap.values():
                charMap[s[i]] = t[i]
            else:
                return False
        else:
            if charMap[s[i]] != t[i]:
                return False
           
    return True

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