結果

問題 No.1927 AB-CD
ユーザー 箱星箱星
提出日時 2022-05-16 21:12:37
言語 Kotlin
(1.9.23)
結果
AC  
実行時間 392 ms / 2,000 ms
コード長 2,926 bytes
コンパイル時間 15,158 ms
コンパイル使用メモリ 453,912 KB
実行使用メモリ 64,984 KB
最終ジャッジ日時 2024-09-14 14:20:48
合計ジャッジ時間 27,507 ms
ジャッジサーバーID
（参考情報） 		judge4 / judge3
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 290 ms
58,468 KB
testcase_01 AC 293 ms
58,304 KB
testcase_02 AC 290 ms
58,192 KB
testcase_03 AC 286 ms
58,368 KB
testcase_04 AC 383 ms
64,984 KB
testcase_05 AC 386 ms
58,492 KB
testcase_06 AC 384 ms
58,116 KB
testcase_07 AC 383 ms
57,780 KB
testcase_08 AC 297 ms
50,880 KB
testcase_09 AC 388 ms
58,704 KB
testcase_10 AC 384 ms
57,316 KB
testcase_11 AC 385 ms
58,040 KB
testcase_12 AC 330 ms
54,468 KB
testcase_13 AC 379 ms
55,360 KB
testcase_14 AC 299 ms
50,368 KB
testcase_15 AC 312 ms
52,484 KB
testcase_16 AC 384 ms
58,204 KB
testcase_17 AC 386 ms
56,892 KB
testcase_18 AC 381 ms
57,028 KB
testcase_19 AC 383 ms
57,300 KB
testcase_20 AC 385 ms
59,172 KB
testcase_21 AC 385 ms
57,572 KB
testcase_22 AC 321 ms
53,824 KB
testcase_23 AC 385 ms
60,176 KB
testcase_24 AC 380 ms
60,792 KB
testcase_25 AC 392 ms
60,920 KB
testcase_26 AC 384 ms
60,708 KB
testcase_27 AC 295 ms
49,868 KB
testcase_28 AC 298 ms
49,836 KB
testcase_29 AC 292 ms
49,856 KB
権限があれば一括ダウンロードができます

ソースコード

diff # 

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

fun PrintWriter.solve() {
    val n = nextInt()
    val s = nextLine()
    val a = s.count { it == 'A' }
    val b = s.count { it == 'B' }
    println(binomSimple(n.toLong(), a + b.toLong()))
}

// 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"
    }
}

class ModIntArray(n: Int) {
    private val a = LongArray(n) { 0L }

    constructor(n: Int, init: (Int) -> ModInt) : this(n) {
        for (i in 0 until n) {
            a[i] = init(i).x
        }
    }

    operator fun set(i: Int, x: ModInt) {
        a[i] = x.x
    }

    operator fun get(i: Int): ModInt {
        return ModInt(a[i])
    }

    fun joinToString(s: String = ", "): String {
        return a.joinToString(s)
    }
}

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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