0205-isomorphic-strings.kt

class Solution {
    fun isIsomorphic(s: String, t: String): Boolean {
        val hm = HashMap<Char, Char>()
        
        for (i in 0 until s.length) {
            if (s[i] !in hm.keys) {
                if (t[i] in hm.values) return false
                hm.put(s[i], t[i])
            } else if (hm.get(s[i]) != t[i]) {
                return false
            }
        }
        
        return true
    }
}