205.Isomorphic Strings

TestCase

aa vs ab

class Solution {
    public boolean isIsomorphic(String s, String t) {
        int n1 = s.length();
        int n2 = t.length();
        if(n1 != n2)
            return false;
        Map<Character, Character> map1 = new HashMap<>();
        Map<Character, Character> map2 = new HashMap<>();

        for(int i = 0; i < n1; i++){
            char c1 = s.charAt(i);
            char c2 = t.charAt(i);
            if(map1.containsKey(c1)){
                if(map1.get(c1) != c2)
                    return false;
            }
            else if(map2.containsKey(c2)){
                if(map2.get(c2) != c1)
                    return false;
            }
            else{
                map1.put(c1, c2);
                map2.put(c2, c1);
            }
        }
        return true;
    }
}