結果

問題 No.2384 Permutations of Permutations
ユーザー 👑 箱箱
提出日時 2023-02-24 03:55:40
言語 Kotlin
(1.9.23)
結果
WA  
実行時間 -
コード長 2,518 bytes
コンパイル時間 16,249 ms
コンパイル使用メモリ 433,016 KB
実行使用メモリ 59,112 KB
最終ジャッジ日時 2023-10-13 14:00:40
合計ジャッジ時間 25,082 ms
ジャッジサーバーID
（参考情報） 		judge14 / judge12
このコードへのチャレンジ
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テストケース

テストケース表示
入力 結果 実行時間
実行使用メモリ
testcase_00 AC 292 ms
55,196 KB
testcase_01 AC 296 ms
53,396 KB
testcase_02 AC 291 ms
55,020 KB
testcase_03 AC 292 ms
53,028 KB
testcase_04 AC 292 ms
53,372 KB
testcase_05 AC 322 ms
57,812 KB
testcase_06 AC 320 ms
58,196 KB
testcase_07 AC 295 ms
53,340 KB
testcase_08 AC 292 ms
53,176 KB
testcase_09 AC 291 ms
53,028 KB
testcase_10 WA -
testcase_11 WA -
testcase_12 WA -
testcase_13 WA -
testcase_14 AC 295 ms
53,312 KB
testcase_15 AC 312 ms
56,008 KB
testcase_16 AC 305 ms
56,964 KB
testcase_17 AC 320 ms
57,956 KB
testcase_18 AC 302 ms
59,112 KB
testcase_19 AC 290 ms
54,960 KB
testcase_20 AC 292 ms
55,276 KB
testcase_21 AC 302 ms
55,472 KB
testcase_22 AC 293 ms
53,288 KB
testcase_23 AC 320 ms
55,740 KB
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ソースコード

diff # 

import java.io.PrintWriter
import java.util.*
import kotlin.math.*

fun PrintWriter.solve() {
    val n = nextInt()
    val k = nextInt()
    var ans = ModInt(k) * (1..n - k).map { ModInt(it) }.fold(ModInt(1), ModInt::times)
    if (n == 2) {
        ans = ModInt(1)
    }
    println(ans)
}

// region ModInt
class ModInt(x: Long) {
    companion object {
        const val MOD = 998244353L
        //const val MOD = 1000000007L
    }

    constructor(y: Int) : this(y.toLong())

    val x = (x % MOD + MOD) % MOD

    operator fun plus(other: ModInt): ModInt {
        return ModInt(x + other.x)
    }

    operator fun minus(other: ModInt): ModInt {
        return ModInt(x - other.x)
    }

    operator fun times(other: ModInt): ModInt {
        return ModInt(x * other.x)
    }

    operator fun div(other: ModInt): ModInt {
        return this * other.inv()
    }

    fun pow(exp: Long): ModInt {
        if (exp == 0L) return ModInt(1L)
        var a = pow(exp shr 1)
        a *= a
        if (exp and 1L == 0L) return a
        return this * a
    }

    fun inv(): ModInt {
        return this.pow(MOD - 2)
    }

    override fun equals(other: Any?): Boolean {
        if (this === other) return true
        if (javaClass != other?.javaClass) return false

        other as ModInt

        if (x != other.x) return false

        return true
    }

    override fun hashCode(): Int {
        return x.hashCode()
    }

    override fun toString(): String {
        return "$x"
    }
}

fun Long.toModInt(): ModInt {
    return ModInt(this)
}

fun Int.toModInt(): ModInt {
    return ModInt(this)
}

fun binomSimple(n: Long, k: Long): ModInt {
    var numer = ModInt(1)
    var denom = ModInt(1)
    for (i in 0 until k) {
        numer *= ModInt(n - i)
        denom *= ModInt(k - i)
    }
    return numer / denom
}
// endregion

fun main() {
    Thread(null, {
        val writer = PrintWriter(System.out, false)
        writer.solve()
        writer.flush()
    }, "solve", abs(1L.shl(26)))
        .apply { setUncaughtExceptionHandler { _, e -> e.printStackTrace(); kotlin.system.exitProcess(1) } }
        .apply { start() }.join()
}

// region Scanner
private var st = StringTokenizer("")
private val br = System.`in`.bufferedReader()

fun next(): String {
    while (!st.hasMoreTokens()) st = StringTokenizer(br.readLine())
    return st.nextToken()
}

fun nextInt() = next().toInt()
fun nextLong() = next().toLong()
fun nextLine() = br.readLine()
fun nextDouble() = next().toDouble()
// endregion
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