Minimize Unique - KOTLIN

// Author : Saurav Kalsoor
// Minimize Unique Numbers - KOTLIN

import java.util.*

var sc = Scanner(System.`in`)
fun main() {
    val n: Int = sc.nextInt()
    val k: Int = sc.nextInt()
    val arr = ArrayList<Int>()
    for (i in 0 until n) {
        arr.add(sc.nextInt())
    }
    println(minimizeUnique(arr, k))
}

fun minimizeUnique(arr: ArrayList<Int>, k: Int): Int {
    var k = k
    val count = HashMap<Int, Int>()
    for (num in arr) {
        count[num] = count.getOrDefault(num, 0) + 1
    }
    val st: MutableSet<MyPair> =
        TreeSet { a, b ->
            if (a.second == b.second)
                a.first - b.first
            else a.second - b.second
        }

    for ((key, value)  in count) {
        st.add(MyPair(key, value))
    }

    var res = st.size
    for (x in st) {
        k -= if (k >= x.second) {
            res--
            x.second
        } else {
            break
        }
    }
    return res
}

internal class MyPair(var first: Int, var second: Int)