Sort By Primes - KOTLIN

// Author : Saurav Kalsoor
// Sort By Primes - KOTLIN

import java.util.*

var sc: Scanner = Scanner(System.`in`)

fun main() {
    val n: Int = sc.nextInt()
    val arr: ArrayList<Int> = ArrayList<Int>()
    for (i in 0 until n) {
        val input: Int = sc.nextInt()
        arr.add(input)
    }
    val result: ArrayList<Int> = sortPrimeNonPrime(arr, n)
    for (i in 0 until n) print(result.get(i).toString() + " ")
    println()
}

fun sortPrimeNonPrime(arr: ArrayList<Int>, n: Int): ArrayList<Int> {
    val maxLimit = 10001
    val primesSet: HashSet<Int> = HashSet<Int>()
    val isPrime = BooleanArray(maxLimit)

    for (i in 2 until maxLimit) isPrime[i] = true

    for (i in 2 until maxLimit) {
        if (isPrime[i]) {
            primesSet.add(i)
            var j: Int = i * i
            while (j < maxLimit) {
                isPrime[j] = false
                j += i
            }
        }
    }
    val primes: ArrayList<Int> = ArrayList<Int>()
    val nonPrimes: ArrayList<Int> = ArrayList<Int>()
    for (i in 0 until n) {
        if (primesSet.contains(arr.get(i))) {
            primes.add(arr.get(i))
        } else {
            nonPrimes.add(arr.get(i))
        }
    }

    Collections.sort(primes)
    Collections.sort(nonPrimes, Collections.reverseOrder())

    val result: ArrayList<Int> = ArrayList<Int>()
    var j = 0
    var k = 0

    for (i in 0 until n) {
        if (primesSet.contains(arr.get(i))) {
            result.add(primes.get(j))
            j++
        } else {
            result.add(nonPrimes.get(k))
            k++
        }
    }
    return result
}