205_Isomorphic_Strings.cpp

/*
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.
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
Constraints:
1 <= s.length <= 5 * 104
t.length == s.length
s and t consist of any valid ascii character
*/
class Solution {
public:
    bool isIsomorphic(string s, string t) {
        vector<int> indexS(200, 0); // Stores index of characters in string s
        vector<int> indexT(200, 0); // Stores index of characters in string t
        
        int len = s.length(); // Get the length of both strings
        
        if(len != t.length()) { // If the lengths of the two strings are different, they can't be isomorphic
            return false;
        }
        
        for(int i = 0; i < len; i++) { // Iterate through each character of the strings
            if(indexS[s[i]] != indexT[t[i]]) { // Check if the index of the current character in string s is different from the index of the corresponding character in string t
                return false; // If different, strings are not isomorphic
            }
            
            indexS[s[i]] = i + 1; // updating position of current character
            indexT[t[i]] = i + 1;
        }
        
        return true; // If the loop completes without returning false, strings are isomorphic
    }
};