Group Anagrams

anagrams.kt

package org.kotlinlang.play

fun main() {
    val sample = listOf("eat","tea","tan","ate","nat","bat")
    
    println(anagrams(sample))
}


fun anagrams(words: List<String>): List<List<String>> {
    val hashMap = hashMapOf<String, List<String>>()

    words.forEach { word ->
        val newWord = word.toCharArray().sortedArray().concatToString()

        if (hashMap.containsKey(newWord)) {
            val list = hashMap[newWord] ?: listOf()
            val muList = list.toMutableList()
            muList.add(word)

            hashMap[newWord] = muList
        } else {
            hashMap[newWord] = listOf(word)
        }
    }

    return hashMap.keys.map {
        hashMap[it]!!
    }
}

Playgound:

https://pl.kotl.in/HJhIhjeNg