[Leetcode 205, Easy] Isomorphic Strings

Problem:

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.

For example,
Given "egg", "add", return true.

Given "foo", "bar", return false.

Given "paper", "title", return true.

Analysis:

Solutions:

C++:

    bool isIsomorphic(string s, string t) {
        if(s.size() != t.size())
            return false;
            
        if(s.empty() && t.empty())
            return true;
        
        map<char, char> map_s_to_t;
        bool map_t_to_s[256] = {false};
        int size = s.size();
        for(int i = 0; i < size; ++i) {
            if(map_s_to_t.find(s[i]) == map_s_to_t.end()) {
                if(map_t_to_s[int(t[i])])
                    return false;
                map_s_to_t[int(s[i])] = int(t[i]);
                map_t_to_s[int(t[i])] = true;
            } else {
                if(t[i] != map_s_to_t[s[i]])
                    return false;
            }
        }
        
        return true;
    }

Java:

Python: