Sort By Indices - KOTLIN

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

import java.util.*

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

fun main() {
    val n: Int = sc.nextInt()
    val m: Int = sc.nextInt()
    val arr: ArrayList<Int> = ArrayList<Int>()
    val indices: ArrayList<Int> = ArrayList<Int>()

    for (i in 0 until n) {
        val input: Int = sc.nextInt()
        arr.add(input)
    }
    for (i in 0 until m) {
        val input: Int = sc.nextInt()
        indices.add(input)
    }
    val result: ArrayList<Int> = sortByIndices(arr, indices, n, m)

    for (i in 0 until n)
        print(result.get(i).toString() + " ")
    println()
}

fun sortByIndices(arr: ArrayList<Int>, indices: ArrayList<Int>, n: Int, m: Int): ArrayList<Int> {
    val sortDesc: ArrayList<Int> = ArrayList<Int>()
    val sortAsc: ArrayList<Int> = ArrayList<Int>()
    val indicesSet: HashSet<Int> = HashSet<Int>()

    for (i in 0 until m) {
        indicesSet.add(indices.get(i))
    }

    for (i in 0 until n) {
        if (indicesSet.contains(i)) {
            sortDesc.add(arr.get(i))
        } else {
            sortAsc.add(arr.get(i))
        }
    }

    Collections.sort(sortDesc, Collections.reverseOrder())
    Collections.sort(sortAsc)

    val result: ArrayList<Int> = ArrayList<Int>()

    var j = 0
    var k = 0

    for (i in 0 until n) {
        if (indicesSet.contains(i)) {
            result.add(sortDesc.get(j))
            j++
        } else {
            result.add(sortAsc.get(k))
            k++
        }
    }
    return result
}