Isomporphic Strings

Link

Just used a hashmap as a mapping technique and created a getKey function to have bijection mapping.

Full Solution in Java:

 public class Solution {
    public boolean isIsomorphic(String s, String t) {
HashMap< Character,Character> maps = new HashMap< Character,Character>();
        
        
        for(int i=0; i< s.length(); i++){
            
            char c = s.charAt(i);
            char x = t.charAt(i);
            
            if(maps.containsKey(c)){
                if(x!=maps.get(c)){
                    return false;
                }
            }
            else if(maps.containsValue(x)){
                if(c!=getKey(maps, x)){
                    return false;
                }
            }
            else{
                maps.put(c,x);
            }
        }
        return true;
    }
    
    
    static Character getKey(HashMap< Character,Character> maps, char value){
        for ( char key : maps.keySet() ) {
            if(maps.get(key)==value){
                return key;
            }
        }
        return null;
    }
}