Description

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.

Approach

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class Solution:
    def isIsomorphic(self, s: str, t: str) -> bool:
        char_index_s = {}
        char_index_t = {}

        for i in range(len(s)):
            if s[i] not in char_index_s:
                char_index_s[s[i]] = i

            if t[i] not in char_index_t:
                char_index_t[t[i]] = i
            
            if char_index_s[s[i]] != char_index_t[t[i]]:
                return False

        return True
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class Solution:
    def isIsomorphic(self, s: str, t: str) -> bool:
        if len(s) != len(t):
            return False
        
        n = [1]*len(s)
        m = [1]*len(t)
        for i in range(len(s)):
            for j in range(i-1,-1,-1):
                f = False
                if s[j] == s[i]:
                    n[i] = n[j]+1
                    f = True
                if t[j] == t[i]:
                    m[i] = m[j]+1
                    f = True
                if f:
                    break
        flag = True
        for k in range(len(s)):
            if n[k] != m[k]:
                flag = False

        return flag