Решение

import java.io.BufferedReader
import java.io.BufferedWriter
import java.io.InputStreamReader
import java.io.OutputStreamWriter
import java.util.PriorityQueue

data class CarInfo(
    val nextUse: Int,
    val id: Int
): Comparable<CarInfo> {
    override fun compareTo(other: CarInfo): Int {
        return nextUse.compareTo(other.nextUse)
    }
}

fun main() {
    val reader = BufferedReader(InputStreamReader(System.`in`))
    val writer = BufferedWriter(OutputStreamWriter(System.out))

    val (N, K, P) = reader.readLine().split(" ").map { it.toInt() }

    val requests = IntArray(P)
    for (i in 0 until P) {
        requests[i] = reader.readLine().toInt()
    }
    reader.close()

    val positions = Array(N + 1) { ArrayDeque<Int>() }
    for (i in 0 until P) {
        val car = requests[i]
        positions[car].addLast(i)
    }
    for (car in 1..N) {
        positions[car].addLast(P + 1)
    }

    val onFloor = HashSet<Int>(K)
    val nextOccur = IntArray(N + 1) { P + 1 }

    val pq = PriorityQueue<CarInfo>(compareByDescending<CarInfo> { it.nextUse })

    var ops = 0

    for (i in 0 until P) {
        val car = requests[i]
        positions[car].removeFirst()
        val nxt = positions[car].firstOrNull() ?: (P + 1)
        nextOccur[car] = nxt

        if (car in onFloor) {
            pq.add(CarInfo(nxt, car))
        } else {
            ops++
            if (onFloor.size < K) {
                onFloor.add(car)
                pq.add(CarInfo(nxt, car))
            } else {
                while (true) {
                    val top = pq.poll() ?: break
                    val c = top.id
                    if ((c in onFloor) && top.nextUse == nextOccur[c]) {
                        onFloor.remove(c)
                        break
                    }
                }

                onFloor.add(car)
                pq.add(CarInfo(nxt, car))
            }
        }
    }

    writer.write("$ops\\n")
    writer.close()
}