Help Mocha - KOTLIN

package com.company

import java.util.*


fun main() {
    val sc = Scanner(System.`in`)
    val n = sc.nextInt()
    val likes = Array(n) { IntArray(2) }
    for (i in 0 until n) {
        likes[i][0] = sc.nextInt()
        likes[i][1] = sc.nextInt()
    }

    val resultArray = helpMocha(likes, n)
    for (a in resultArray) print("$a ")
    println()
}


fun helpMocha(likes: Array<IntArray>, n: Int): IntArray {
    val mp = HashMap<Int, HashSet<Int>>()
    val resultSet = HashSet<Int>()
    for (like in likes) {
        if (!mp.containsKey(like[0])) {
            mp[like[0]] = HashSet()
        }
        val temp = mp[like[0]]!!
        temp.add(like[1])
        mp[like[0]] = temp
        if (mp.containsKey(like[1]) && mp[like[1]]!!.contains(like[0])) {
            resultSet.add(like[0])
            resultSet.add(like[1])
        }
    }
    if (resultSet.isEmpty()) return intArrayOf(-1)
    val resultArray = IntArray(resultSet.size)
    var i = 0
    for (a in resultSet) {
        resultArray[i] = a
        i++
    }
    Arrays.sort(resultArray)
    return resultArray
}