Isomorphic Strings

Problem Statement - link #

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.

Examples #

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 * 10^4
• t.length == s.length
• s and t consist of any valid ascii character.

Solutions #

class Solution {
public:
    bool isIsomorphic(string s, string t) {
      map<char,char> mp, np;
      for(int i=0; i<s.size(); i++){
        if(mp.find(s[i]) == mp.end()) mp[s[i]] = t[i];
        else if(mp[s[i]] != t[i]) return false;
        if(np.find(t[i]) == np.end()) np[t[i]] = s[i];
        else if(np[t[i]] != s[i]) return false;
      }
      return true;
    }
};