結果

問題 No.2794 I Love EDPC-T
コンテスト
ユーザー 箱星
提出日時 2023-01-31 09:49:33
言語 Kotlin
(2.1.0)
結果
MLE  
実行時間 -
コード長 3,112 bytes
コンパイル時間 19,504 ms
コンパイル使用メモリ 463,740 KB
実行使用メモリ 564,484 KB
最終ジャッジ日時 2024-12-20 21:15:55
合計ジャッジ時間 130,951 ms
ジャッジサーバーID
（参考情報） 		judge1 / judge4
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 3
other AC * 8 TLE * 22 MLE * 1
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()
    if (s.all { it == '>' }) {
        println(0)
        return
    }
    val dp = Array(n) { Array(n) { Array(2) { ModInt(0) } } }
    dp[0][0][0] = ModInt(1)
    for (i in 0 until n - 1) {
        for (j in 0..i) {
            if (s[i] == '>') {
                dp[i + 1][j][0] += dp[i][j][0] + dp[i][j][1]
            }
            dp[i + 1][j + 1][1] += dp[i][j][0]
        }
    }
    val c = Array(n + 1) { i -> binomSimple(2L * i, i.toLong()) / ModInt(i + 1) }
    var ans = ModInt(0)
    val p = s.count { it == '<' } % 2
    for (i in 0 until n) {
        val num = c[n - i] * (dp[n - 1][i][0] + dp[n - 1][i][1])
        if (i % 2 == p) {
            ans += num
        } else {
            ans -= num
        }
    }
    println(ans)
}

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

    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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