Question

How to check if two strings are isomorphic in Kotlin

Answer 1

fun areIsomorphic(s: String, t: String): Boolean {
    if (s.length != t.length) return false

    val mapST = mutableMapOf<Char, Char>()
    val mapTS = mutableMapOf<Char, Char>()

    for ((c1, c2) in s.zip(t)) {
        // Check mapping from s → t
        if (mapST.containsKey(c1)) {
            if (mapST[c1] != c2) return false
        } else {
            mapST[c1] = c2
        }

        // Check mapping from t → s
        if (mapTS.containsKey(c2)) {
            if (mapTS[c2] != c1) return false
        } else {
            mapTS[c2] = c1
        }
    }
    
    return true
}

fun main() {
    println(areIsomorphic("egg", "add"))     
    println(areIsomorphic("foo", "bar"))     
    println(areIsomorphic("paper", "title")) 
}



/*
run:

true
false
true

*/

 

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Answer 2

fun areIsomorphic(s: String, t: String): Boolean {
    fun pattern(str: String) = str.map { str.indexOf(it) }
    
    return pattern(s) == pattern(t)
}

fun main() {
    println(areIsomorphic("egg", "add"))     
    println(areIsomorphic("foo", "bar"))     
    println(areIsomorphic("paper", "title")) 
}



/*
run:

true
false
true

*/

 

70+ SQL courses for beginners and professionals